<PAGE>
 

     As filed with the Securities and Exchange Commission on June 19, 1998
                                                      Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                ---------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                     Under
                           The Securities Act of 1933

                           PLATINUM technology, inc.
             (Exact name of registrant as specified in its charter)

           Delaware                                          36-3509662
(State or other jurisdiction of                     (IRS Employer Identification
of incorporation or organization)                              Number)

    1815 South Meyers Road, Oakbrook Terrace, Illinois 60181, (630) 620-5000
          (Address of Principal Executive Offices including Zip Code)

     Mastering, Inc. Amended and Restated 1995 Executive Stock Option Plan
      Mastering, Inc. Amended and Restated 1995 Employee Stock Option Plan
    Mastering, Inc. 1998 Non-Qualified Stock Option Agreement for Employees
            Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan
                       LBMS Executive Share Option Scheme
                        LBMS 1996 Equity Incentive Plan
                 VIVID Publishing, Inc. 1997 Stock Option Plan
                 VIVID Publishing, Inc. 1996 Stock Option Plan
                             (Full title of plans)

                              Andrew J. Filipowski
    1815 South Meyers Road, Oakbrook Terrace, Illinois 60181, (630) 620-5000
           (Name, address and telephone number of agent for service)

                                   Copies to:
                             Matthew S. Brown, Esq.
                               Mark D. Wood, Esq.
                             Katten Muchin & Zavis
                           525 W. Monroe, Suite 1600
                            Chicago, IL  60661-3693
                           Fax Number: (312) 902-1061

                                ---------------

<TABLE>
<CAPTION>
                                           CALCULATION OF REGISTRATION FEE
=============================================================================================================================
                                                                     Proposed maximum    Proposed maximum     
                                                                      offering price    aggregate offering       Amount of   
 Title of securities to be registered   Amount to be registered(1)      per share             price          registration fee
-----------------------------------------------------------------------------------------------------------------------------
<S>                                     <C>                          <C>                <C>                  <C>
Common Stock, $.001 par value.........     2,193,219 shares(2)          $15.38(2)       $33,731,708(2)           $ 9,951
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........     1,160,609 shares(3)          $11.58(3)       $13,439,852(3)           $ 3,965
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........      100,945 shares(4)           $19.46(4)       $ 1,964,390(4)           $   580
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........       57,178 shares(5)           $ 1.99          $   113,784              $    34
---------------------------------------=====================================================================-----------------
TOTAL                                           3,511,951                               $49,249,734              $14,530
=============================================================================================================================
</TABLE>

(1) Includes an indeterminate number of shares of common stock, par value $.001
    per share, of PLATINUM technology, inc. ("PLATINUM Common Stock") that may
    be issuable by reason of stock splits, stock dividends or similar
    transactions.  Also includes associated rights (the "Rights") to purchase
    1/100 of a share of Series A Participating Preferred Stock, par value $.01
    per share, of PLATINUM technology, inc.  The Rights initially attached to
    and trade with PLATINUM Common Stock.  The value attributable to such
    Rights, if any, is reflected in the market price of the PLATINUM Common
    Stock.
(2) Represents shares issuable upon exercise of outstanding options under the
    Mastering, Inc. Amended and Restated 1995 Executive Stock Option Plan, the
    Mastering, Inc. Amended and Restated 1995 Employee Stock Option Plan, and
    the Mastering, Inc. 1998 Non-Qualified Stock Option Agreements for Employees
    (the "Mastering Plans").  The dollar amounts are based upon the weighted
    average exercise price of the shares subject to outstanding options under
    the Mastering Plans.
(3) Represents shares issuable upon exercise of outstanding options under the
    Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic Works
    Plan").  The dollar amounts are based upon the weighted average exercise
    price of the shares subject to outstanding options under the Logic Works
    Plan.
(4) Represents shares issuable upon exercise of outstanding options under the
    LBMS Executive Share Option Scheme, and the LBMS 1996 Equity Incentive Plan
    (the "LBMS Plans").  The dollar amounts are based upon the weighted average
    exercise price of the shares subject to outstanding options under the LBMS
    Plans.
(5) Represents shares issuable upon exercise of outstanding options under the
    Vivid Publishing, Inc. 1997 Stock Option Plan and the Vivid Publishing, Inc.
    1996 Stock Option Plan (the "Vivid Plans"). The dollar amounts are based
    upon the weighted average exercise price of the shares subject to
    outstanding options under the Vivid Plans.
================================================================================
<PAGE>
 
                                     PART I
                     INFORMATION REQUIRED IN THE PROSPECTUS

     The information called for in Part I of Form S-8 is currently included in:
(i) the prospectuses for the Mastering, Inc. Amended and Restated 1995 Executive
Stock Option Plan, the Mastering, Inc. Amended and Restated 1995 Employee Stock
Option Plan and the Mastering, Inc. 1998 Non-Qualified Stock Option Agreements
for Employees (the "Mastering Plans"); (ii) the prospectus for the Logic Works,
Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic Works Plan"); (iii) the
prospectuses for the LBMS Executive Share Option Scheme and the LBMS 1996 Equity
Incentive Plan (the "LBMS Plans"); and (iv) the prospectuses for the Vivid
Publishing, Inc. 1997 Stock Option Plan and the Vivid Publishing, Inc. 1996
Stock Option Plan (the "Vivid Plans") and is not being filed with or included in
this Form S-8 in accordance with the rules and regulations of the Securities and
Exchange Commission (the "Commission").

     The Mastering Plans were assumed by PLATINUM technology, inc. (the
"Company") pursuant to the Agreement and Plan of Merger, dated as of February
18, 1998, among the Company, PT Acquisition Corporation I and Mastering, Inc.
Options previously issued under the Mastering Plans converted into options to
purchase shares of the Company's Common Stock, $.001 par value per share
("Common Stock"). The Logic Works Plan was assumed by the Company pursuant to
the Agreement and Plan of Merger, dated as of March 14, 1998, among the Company,
PT Acquisition Corporation II and Logic Works, Inc. Options previously issued
under the Logic Works Plan converted into options to purchase shares of Common
Stock. The LBMS Plans were adopted by the Company in order to give effect to
certain provisions of the Agreement and Plan of Reorganization, dated January 2,
1998, by and between the Company and Learmonth & Burchett Management Systems
Plc. ("LBMS") as such provisions relate to unexercised options previously
granted by LBMS under The Learmonth & Burchett Management Systems Executive
Share Option Scheme and the Learmonth & Burchett Management Systems 1996 Equity
Incentive Plan. The Vivid Plans were assumed by the Company pursuant to the
Agreement and Plan of Reorganization by and among the Company, VSI Acquisition 
Corp., Vivid Publishing, Inc. and certain of the shareholders of Vivid 
Publishing, Inc., dated as of May 29, 1998. Options previously issued under the
Vivid Plans converted into options to purchase shares of Common Stock. No
additional options will be issued under the Mastering Plans, the Logic Works
Plan, the LBMS Plans, or the Vivid Plans.

                                       2
<PAGE>
 
                                    PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

     The following documents have been filed by the Company with the Commission
under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and
are incorporated in this Registration Statement by reference:

     1.   The Company's Annual Report on Form 10-K for the year ended December
          31, 1997;

     2.   The Company's Quarterly Report on Form 10-Q for the quarter ended
          March 31, 1998;

     3.   The Company's Current Reports on Form 8-K dated January 27, 1998,
          March 3, 1998, April 16, 1998, April 21, 1998 (as amended by the
          Current Report on Form 8-K/A dated May 6, 1998) and May 28, 1998;

     4.   The description of the Common Stock contained in the Company's
          Registration Statement on Form 8-A filed March 7, 1991 pursuant to
          Section 12 of the Exchange Act and all amendments thereto and reports
          filed for the purpose of updating such description; and

     5.   The description of the preferred stock purchase rights contained in
          the Company's Registration Statement on Form 8-A filed December 26,
          1995 pursuant to Section 12 of the Exchange Act and all amendments
          thereto and reports filed for the purpose of updating such
          description.

     In addition, all documents filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act, subsequent to the date hereof and prior
to the filing of a post-effective amendment indicating that all securities
offered pursuant to this Registration Statement have been sold or deregistering
all such securities then remaining unsold, shall be deemed to be incorporated by
reference herein and to be part hereof from the date of filing of such
documents.  Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this Registration Statement to the extent that a statement
contained herein or in any subsequently filed document which also is or is
deemed to be incorporated by reference herein modifies or supersedes such
statement.

Item 4.  Description of Securities.

     Not Applicable.

Item 5.  Interests of Named Experts and Counsel.

     Not Applicable.

Item 6.  Indemnification of Directors and Officers.

     Article Ten of the Company's Restated Certificate of Incorporation provides
that the Company shall indemnify its directors to the full extent permitted by
the Delaware General Corporation Law and may indemnify its officers to such
extent, except that the Company shall not be obligated to indemnify any such
person (i) with respect to proceedings, claims or actions initiated or brought
voluntarily by any such person and not by way of defense, or (ii) for any
amounts paid in settlement of an action indemnified against by the Company
without the prior written consent of the Company.  With the approval of its
stockholders, the Company has entered into indemnity agreements with each of its
directors and certain of its officers. These agreements may require the Company,
among other things, to indemnify such officers and directors against certain
liabilities that may arise by reason of their status or service as directors or
officers, to advance expenses to them as they are incurred, provided that they
undertake to repay the amount advanced if it is ultimately determined by a court
that they are

                                       3
<PAGE>
 
not entitled to indemnification, and to obtain directors' and officers'
liability insurance if available on reasonable terms.

     In addition, Article Nine of the Company's Restated Certificate of
Incorporation provides that a director of the Company shall not be personally
liable to the Company or its stockholders for monetary damages for breach of his
or her fiduciary duty as a director, except for liability (i) for any breach of
the director's duty of loyalty to the Company or its stockholders, (ii) for acts
or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the General Corporation Law
of the State of Delaware, or (iv) for any transaction from which the director
derives an improper personal benefit.

     Reference is made to Section 145 of the General Corporation Law of the
State of Delaware which provides for indemnification of directors and officers
in certain circumstances.

     The Company has purchased an insurance policy under which it is entitled to
be reimbursed for certain indemnity payments it is required or permitted to make
to its directors and officers.

Item 7.  Exemption from Registration Claimed.

     Not Applicable.

Item 8.  Exhibits.
 
     4.1   Conformed copy of the Restated Certificate of Incorporation of the
           Company, as amended (incorporated by reference to Exhibit 3.1(d) to
           the Company's Registration Statement on Form S-1, Registration No. 
           333-07783).

     4.2   Bylaws of the Company (incorporated by reference to Exhibit 3.2 to
           the Company's Registration Statement on Form S-1, Registration No. 
           33-39233 (the "IPO S-1")).

     4.3   Mastering, Inc. Amended and Restated 1995 Executive Stock Option Plan
           (the "Mastering Executive Plan") (incorporated by reference to
           Exhibit 4.7 to Mastering, Inc.'s Registration Statement on Form S-8,
           Registration No. 333-42949 (the "Mastering S-8")).

     4.4   Mastering, Inc. Amended and Restated 1995 Employee Stock Option Plan
           (the "Mastering Employee Plan") (incorporated by reference to Exhibit
           4.8 to the Mastering S-8).

     4.5   Form of Mastering, Inc. 1998 Non-Qualified Stock Option Agreement For
           Employees.

     4.6   Form of Stock Option Agreement under the Mastering Executive Plan.

     4.7   Form of Stock Option Agreement under the Mastering Employee Plan.

     4.8   Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic
           Plan").

     4.9   Form of Stock Option Agreement under the Logic Plan (incorporated by
           reference to Exhibit 99.3 to Logic Works, Inc.'s Registration
           Statement on Form S-8, Registration No. 33-98212 (the "Logic S-8").

     4.10  Form of Automatic Stock Option Agreement under the Logic Plan
           (incorporated by reference to Exhibit 99.8 to the Logic S-8).

     4.11  LBMS Executive Share Option Scheme (the "LBMS Option Scheme").

     4.12  LBMS 1996 Equity Incentive Plan (the "LBMS Incentive Plan").

                                       4
<PAGE>
 

     4.13  Vivid Publishing, Inc. 1997 Stock Option Plan.

     4.14  Vivid Publishing, Inc. 1996 Stock Option Plan.

     4.15  Form of Stock Option Agreement under the Vivid Publishing, Inc. 1997
           Stock Option Plan.

     4.16  Form of Stock Option Agreement under the Vivid Publishing, Inc.
           1996 Stock Option Plan.

     4.17  Specimen stock certificate representing Common Stock (incorporated
           by reference to Exhibit 4.1 to the IPO S-1).

     4.18  Rights Agreement dated as of December 21, 1995, between the Company
           and Harris Trust and Savings Bank (incorporated by reference to
           Exhibit 1 to the Company's Registration Statement on Form 8-A, filed
           December 26, 1995).

     5     Opinion of counsel as to legality of shares of Common Stock being
           offered (including consent).

    15     Acknowledgment of KPMG Peat Marwick LLP Regarding Independent 
           Auditors' Review Report.

    23.1   Consent of KPMG Peat Marwick LLP.

    23.2   Consent of Katten Muchin & Zavis (included in their opinion filed as
           Exhibit 5 herein).

    24     Power of Attorney (included on the signature page of this 
           Registration Statement).

Item 9.  Undertakings.

     1.   The Company hereby undertakes:

          (a) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this Registration Statement:

                    (i) To include any prospectus required by Section 10(a)(3)
          of the Securities Act of 1933;

                    (ii) To reflect in the prospectus any facts or events
          arising after the effective date of the Registration Statement (or the
          most recent post-effective amendment thereof) which, individually, or
          in the aggregate, represent a fundamental change in the information
          set forth in the Registration Statement.  Notwithstanding the
          foregoing, any increase or decrease in volume of securities offered
          (if the total dollar value of securities offered would not exceed that
          which was registered) and any deviation from the low or high end of
          the estimated maximum offering range may be reflected in the form of
          prospectus filed with the Commission pursuant to Rule 424(b) if, in
          the aggregate, the changes in volume and price represent no more than
          a 20 percent change in the maximum aggregate offering price set forth
          in the "Calculation of Registration Fee" table in the effective
          registration statement;

                    (iii) To include any material information with respect to
          the plan of distribution not previously disclosed in the Registration
          Statement or any material change to such information in the
          Registration Statement;

     provided, however, that paragraphs (a)(i) and (a)(ii) do not apply if the
     information required to be included in a post-effective amendment by those
     paragraphs is contained in periodic reports filed with or furnished to the
     Commission by the Company pursuant to Section 13 or Section 15(d) of the
     Exchange Act that are incorporated by reference in the Registration
     Statement.

                                       5
<PAGE>
 
          (b) That, for the purpose of determining any liability under the
     Securities Act of 1933, each such post-effective amendment shall be deemed
     to be a new registration statement relating to the securities offered
     therein, and the offering of such securities at that time shall be deemed
     to be the initial bona fide offering thereof.

          (c) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.

     2.   The Company hereby undertakes that, for the purpose of determining any
liability under the Securities Act of 1933, each filing of the Company's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the Registration Statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     3.   Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Company and affiliated companies pursuant to the provisions
described in Item 6 above, or otherwise, the Company has been informed that in
the opinion of the Commission such indemnification is against public policy as
expressed in the Securities Act of 1933 and is therefore unenforceable.  In the
event that a claim for indemnification against such liabilities (other than the
payment by the Company of expenses incurred or paid by a director, officer or
controlling person of the Company in the successful defense of any action, suit
or proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Company will, unless in the
opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933 and will be governed by the final adjudication of such issue.

                                       6
<PAGE>
 
                                  SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Company
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Oakbrook Terrace, State of Illinois, on this 18th day
of June, 1998.

                              PLATINUM technology, inc.

                              By:   /s/  ANDREW J. FILIPOWSKI
                                    -------------------------------------
                                    Andrew J. Filipowski
                                    President and Chief Executive Officer


                               POWER OF ATTORNEY

     Each person whose signature appears below hereby constitutes and appoints
Andrew J. Filipowski, Michael P. Cullinane, Larry S. Freedman and Matthew S.
Brown, and each of them, his true and lawful attorneys-in-fact and agents, with
full power of substitution, to sign on his behalf, individually and in each
capacity stated below, all amendments and post-effective amendments to this
Registration Statement on Form S-8 and to file the same, with all exhibits
thereto and any other documents in connection therewith, with the Securities and
Exchange Commission under the Securities Act of 1933, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully and to all intents and purposes as each might or could do in
person, hereby ratifying and confirming each act that said attorneys-in-fact and
agents may lawfully do or cause to be done by virtue thereof.

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on this 18th day of June, 1998.

<TABLE>
<CAPTION>

             Signature                                             Title
             ---------                                             -----

<S>                                       <C>
/s/ ANDREW J. FILIPOWSKI             President, Chief Executive Officer
-----------------------------------  (Principal Executive Officer) and a
Andrew J. Filipowski                 Director
                                                                        
/s/ MICHAEL P. CULLINANE             Executive Vice President, Chief Financial
-----------------------------------  Officer (Principal Financial and Accounting
Michael P. Cullinane                 Officer) and a Director
                                   
/s/ PAUL L. HUMENANSKY               Executive Vice President, Chief Operations
-----------------------------------  Officer and a Director
Paul L. Humenansky                  

/s/ JAMES E. COWIE                   Director
-----------------------------------
James E. Cowie

/s/ STEVEN D. DEVICK                 Director
-----------------------------------
Steven D. Devick

/s/ ARTHUR P. FRIGO                  Director
-----------------------------------
Arthur P. Frigo

                                     Director
-----------------------------------
Gian Fulgoni
</TABLE>

                                       7
<PAGE>
 

 Exhibit                           Description of Exhibit
 Number                            ----------------------
 ------

   4.5      Form of Mastering, Inc. 1998 Non-Qualified Stock Option Agreement
            for Employees.

   4.6      Form of Stock Option Agreement under the Mastering, Inc. Amended and
            Restated 1995 Executive Stock Option Plan.

   4.7      Form of Employee Stock Option Agreement under the Mastering, Inc.
            Amended and Restated 1995 Employee Stock Option Plan.

   4.8      Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic
            Plan").

   4.11     LBMS Executive Share Option Scheme (the "LBMS Option Scheme").

   4.12     LBMS 1996 Equity Incentive Plan (the "LBMS Incentive Plan").

   4.13     Vivid Publishing, Inc. 1997 Stock Option Plan.

   4.14     Vivid Publishing, Inc. 1996 Stock Option Plan.

   4.15     Form of Stock Option Agreement under the Vivid Publishing, Inc. 1997
            Stock Option Plan.

   4.16     Form of Stock Option Agreement under the Vivid Publishing, Inc.
            1996 Stock Option Plan.

   5        Opinion of counsel as to legality of shares of Common Stock being
            offered (including consent).

  15        Acknowledgement of KPMG Peat Marwick LLP Regarding Independent
            Auditors' Review Report.

  23.1      Consent of KPMG Peat Marwick LLP with respect to the Company's
            financial statements.

  23.2      Consent of Katten Muchin & Zavis (included in their opinion filed as
            Exhibit 5 herein).

  24        Power of Attorney (included on the signature page of this
            Registration Statement).

                                       8
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 26777}]
{"company-data": {"conformed-name": "PLATINUM TECHNOLOGY INC", "cik": "0000825703", "assigned-sic": "7372", "irs-number": "363509662", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-57311", "film-number": "98651284"}, "business-address": {"street1": "1815 S MEYERS RD", "city": "OAKBROOK TERRACE", "state": "IL", "zip": "60181", "phone": "6306205000"}, "mail-address": {"street1": "1815 S MEYERS RD", "city": "OAKBROOK TERRACE", "state": "IL", "zip": "60181"}}
As filed with the Securities and Exchange Commission on June 19, 1998
                                                      Registration No. 333-
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                ---------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                     Under
                           The Securities Act of 1933

                           PLATINUM technology, inc.
             (Exact name of registrant as specified in its charter)

           Delaware                                          36-3509662
(State or other jurisdiction of                     (IRS Employer Identification
of incorporation or organization)                              Number)

    1815 South Meyers Road, Oakbrook Terrace, Illinois 60181, (630) 620-5000
          (Address of Principal Executive Offices including Zip Code)

     Mastering, Inc. Amended and Restated 1995 Executive Stock Option Plan
      Mastering, Inc. Amended and Restated 1995 Employee Stock Option Plan
    Mastering, Inc. 1998 Non-Qualified Stock Option Agreement for Employees
            Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan
                       LBMS Executive Share Option Scheme
                        LBMS 1996 Equity Incentive Plan
                 VIVID Publishing, Inc. 1997 Stock Option Plan
                 VIVID Publishing, Inc. 1996 Stock Option Plan
                             (Full title of plans)

                              Andrew J. Filipowski
    1815 South Meyers Road, Oakbrook Terrace, Illinois 60181, (630) 620-5000
           (Name, address and telephone number of agent for service)

                                   Copies to:
                             Matthew S. Brown, Esq.
                               Mark D. Wood, Esq.
                             Katten Muchin & Zavis
                           525 W. Monroe, Suite 1600
                            Chicago, IL  60661-3693
                           Fax Number: (312) 902-1061

                                ---------------
CALCULATION OF REGISTRATION FEE
=============================================================================================================================
                                                                     Proposed maximum    Proposed maximum     
                                                                      offering price    aggregate offering       Amount of   
 Title of securities to be registered   Amount to be registered(1)      per share             price          registration fee
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........     2,193,219 shares(2)          $15.38(2)       $33,731,708(2)           $ 9,951
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........     1,160,609 shares(3)          $11.58(3)       $13,439,852(3)           $ 3,965
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........      100,945 shares(4)           $19.46(4)       $ 1,964,390(4)           $   580
-----------------------------------------------------------------------------------------------------------------------------
Common Stock, $.001 par value.........       57,178 shares(5)           $ 1.99          $   113,784              $    34
---------------------------------------=====================================================================-----------------
TOTAL                                           3,511,951                               $49,249,734              $14,530
=============================================================================================================================
(1) Includes an indeterminate number of shares of common stock, par value $.001
    per share, of PLATINUM technology, inc. ("PLATINUM Common Stock") that may
    be issuable by reason of stock splits, stock dividends or similar
    transactions.  Also includes associated rights (the "Rights") to purchase
    1/100 of a share of Series A Participating Preferred Stock, par value $.01
    per share, of PLATINUM technology, inc.  The Rights initially attached to
    and trade with PLATINUM Common Stock.  The value attributable to such
    Rights, if any, is reflected in the market price of the PLATINUM Common
    Stock.
(2) Represents shares issuable upon exercise of outstanding options under the
    Mastering, Inc. Amended and Restated 1995 Executive Stock Option Plan, the
    Mastering, Inc. Amended and Restated 1995 Employee Stock Option Plan, and
    the Mastering, Inc. 1998 Non-Qualified Stock Option Agreements for Employees
    (the "Mastering Plans").  The dollar amounts are based upon the weighted
    average exercise price of the shares subject to outstanding options under
    the Mastering Plans.
(3) Represents shares issuable upon exercise of outstanding options under the
    Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic Works
    Plan").  The dollar amounts are based upon the weighted average exercise
    price of the shares subject to outstanding options under the Logic Works
    Plan.
(4) Represents shares issuable upon exercise of outstanding options under the
    LBMS Executive Share Option Scheme, and the LBMS 1996 Equity Incentive Plan
    (the "LBMS Plans").  The dollar amounts are based upon the weighted average
    exercise price of the shares subject to outstanding options under the LBMS
    Plans.
(5) Represents shares issuable upon exercise of outstanding options under the
    Vivid Publishing, Inc. 1997 Stock Option Plan and the Vivid Publishing, Inc.
    1996 Stock Option Plan (the "Vivid Plans"). The dollar amounts are based
    upon the weighted average exercise price of the shares subject to
    outstanding options under the Vivid Plans.
================================================================================
PART I
                     INFORMATION REQUIRED IN THE PROSPECTUS

     The information called for in Part I of Form S-8 is currently included in:
(i) the prospectuses for the Mastering, Inc. Amended and Restated 1995 Executive
Stock Option Plan, the Mastering, Inc. Amended and Restated 1995 Employee Stock
Option Plan and the Mastering, Inc. 1998 Non-Qualified Stock Option Agreements
for Employees (the "Mastering Plans"); (ii) the prospectus for the Logic Works,
Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic Works Plan"); (iii) the
prospectuses for the LBMS Executive Share Option Scheme and the LBMS 1996 Equity
Incentive Plan (the "LBMS Plans"); and (iv) the prospectuses for the Vivid
Publishing, Inc. 1997 Stock Option Plan and the Vivid Publishing, Inc. 1996
Stock Option Plan (the "Vivid Plans") and is not being filed with or included in
this Form S-8 in accordance with the rules and regulations of the Securities and
Exchange Commission (the "Commission").

     The Mastering Plans were assumed by PLATINUM technology, inc. (the
"Company") pursuant to the Agreement and Plan of Merger, dated as of February
18, 1998, among the Company, PT Acquisition Corporation I and Mastering, Inc.
Options previously issued under the Mastering Plans converted into options to
purchase shares of the Company's Common Stock, $.001 par value per share
("Common Stock"). The Logic Works Plan was assumed by the Company pursuant to
the Agreement and Plan of Merger, dated as of March 14, 1998, among the Company,
PT Acquisition Corporation II and Logic Works, Inc. Options previously issued
under the Logic Works Plan converted into options to purchase shares of Common
Stock. The LBMS Plans were adopted by the Company in order to give effect to
certain provisions of the Agreement and Plan of Reorganization, dated January 2,
1998, by and between the Company and Learmonth & Burchett Management Systems
Plc. ("LBMS") as such provisions relate to unexercised options previously
granted by LBMS under The Learmonth & Burchett Management Systems Executive
Share Option Scheme and the Learmonth & Burchett Management Systems 1996 Equity
Incentive Plan. The Vivid Plans were assumed by the Company pursuant to the
Agreement and Plan of Reorganization by and among the Company, VSI Acquisition 
Corp., Vivid Publishing, Inc. and certain of the shareholders of Vivid 
Publishing, Inc., dated as of May 29, 1998. Options previously issued under the
Vivid Plans converted into options to purchase shares of Common Stock. No
additional options will be issued under the Mastering Plans, the Logic Works
Plan, the LBMS Plans, or the Vivid Plans.

                                       2
PART II
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

     The following documents have been filed by the Company with the Commission
under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and
are incorporated in this Registration Statement by reference:

     1.   The Company's Annual Report on Form 10-K for the year ended December
          31, 1997;

     2.   The Company's Quarterly Report on Form 10-Q for the quarter ended
          March 31, 1998;

     3.   The Company's Current Reports on Form 8-K dated January 27, 1998,
          March 3, 1998, April 16, 1998, April 21, 1998 (as amended by the
          Current Report on Form 8-K/A dated May 6, 1998) and May 28, 1998;

     4.   The description of the Common Stock contained in the Company's
          Registration Statement on Form 8-A filed March 7, 1991 pursuant to
          Section 12 of the Exchange Act and all amendments thereto and reports
          filed for the purpose of updating such description; and

     5.   The description of the preferred stock purchase rights contained in
          the Company's Registration Statement on Form 8-A filed December 26,
          1995 pursuant to Section 12 of the Exchange Act and all amendments
          thereto and reports filed for the purpose of updating such
          description.

     In addition, all documents filed by the Company pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act, subsequent to the date hereof and prior
to the filing of a post-effective amendment indicating that all securities
offered pursuant to this Registration Statement have been sold or deregistering
all such securities then remaining unsold, shall be deemed to be incorporated by
reference herein and to be part hereof from the date of filing of such
documents.  Any statement contained in a document incorporated or deemed to be
incorporated by reference herein shall be deemed to be modified or superseded
for purposes of this Registration Statement to the extent that a statement
contained herein or in any subsequently filed document which also is or is
deemed to be incorporated by reference herein modifies or supersedes such
statement.

Item 4.  Description of Securities.

     Not Applicable.

Item 5.  Interests of Named Experts and Counsel.

     Not Applicable.

Item 6.  Indemnification of Directors and Officers.

     Article Ten of the Company's Restated Certificate of Incorporation provides
that the Company shall indemnify its directors to the full extent permitted by
the Delaware General Corporation Law and may indemnify its officers to such
extent, except that the Company shall not be obligated to indemnify any such
person (i) with respect to proceedings, claims or actions initiated or brought
voluntarily by any such person and not by way of defense, or (ii) for any
amounts paid in settlement of an action indemnified against by the Company
without the prior written consent of the Company.  With the approval of its
stockholders, the Company has entered into indemnity agreements with each of its
directors and certain of its officers. These agreements may require the Company,
among other things, to indemnify such officers and directors against certain
liabilities that may arise by reason of their status or service as directors or
officers, to advance expenses to them as they are incurred, provided that they
undertake to repay the amount advanced if it is ultimately determined by a court
that they are

                                       3
not entitled to indemnification, and to obtain directors' and officers'
liability insurance if available on reasonable terms.

     In addition, Article Nine of the Company's Restated Certificate of
Incorporation provides that a director of the Company shall not be personally
liable to the Company or its stockholders for monetary damages for breach of his
or her fiduciary duty as a director, except for liability (i) for any breach of
the director's duty of loyalty to the Company or its stockholders, (ii) for acts
or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the General Corporation Law
of the State of Delaware, or (iv) for any transaction from which the director
derives an improper personal benefit.

     Reference is made to Section 145 of the General Corporation Law of the
State of Delaware which provides for indemnification of directors and officers
in certain circumstances.

     The Company has purchased an insurance policy under which it is entitled to
be reimbursed for certain indemnity payments it is required or permitted to make
to its directors and officers.

Item 7.  Exemption from Registration Claimed.

     Not Applicable.

Item 8.  Exhibits.
 
     4.1   Conformed copy of the Restated Certificate of Incorporation of the
           Company, as amended (incorporated by reference to Exhibit 3.1(d) to
           the Company's Registration Statement on Form S-1, Registration No. 
           333-07783).

     4.2   Bylaws of the Company (incorporated by reference to Exhibit 3.2 to
           the Company's Registration Statement on Form S-1, Registration No. 
           33-39233 (the "IPO S-1")).

     4.3   Mastering, Inc. Amended and Restated 1995 Executive Stock Option Plan
           (the "Mastering Executive Plan") (incorporated by reference to
           Exhibit 4.7 to Mastering, Inc.'s Registration Statement on Form S-8,
           Registration No. 333-42949 (the "Mastering S-8")).

     4.4   Mastering, Inc. Amended and Restated 1995 Employee Stock Option Plan
           (the "Mastering Employee Plan") (incorporated by reference to Exhibit
           4.8 to the Mastering S-8).

     4.5   Form of Mastering, Inc. 1998 Non-Qualified Stock Option Agreement For
           Employees.

     4.6   Form of Stock Option Agreement under the Mastering Executive Plan.

     4.7   Form of Stock Option Agreement under the Mastering Employee Plan.

     4.8   Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic
           Plan").

     4.9   Form of Stock Option Agreement under the Logic Plan (incorporated by
           reference to Exhibit 99.3 to Logic Works, Inc.'s Registration
           Statement on Form S-8, Registration No. 33-98212 (the "Logic S-8").

     4.10  Form of Automatic Stock Option Agreement under the Logic Plan
           (incorporated by reference to Exhibit 99.8 to the Logic S-8).

     4.11  LBMS Executive Share Option Scheme (the "LBMS Option Scheme").

     4.12  LBMS 1996 Equity Incentive Plan (the "LBMS Incentive Plan").

                                       4
4.13  Vivid Publishing, Inc. 1997 Stock Option Plan.

     4.14  Vivid Publishing, Inc. 1996 Stock Option Plan.

     4.15  Form of Stock Option Agreement under the Vivid Publishing, Inc. 1997
           Stock Option Plan.

     4.16  Form of Stock Option Agreement under the Vivid Publishing, Inc.
           1996 Stock Option Plan.

     4.17  Specimen stock certificate representing Common Stock (incorporated
           by reference to Exhibit 4.1 to the IPO S-1).

     4.18  Rights Agreement dated as of December 21, 1995, between the Company
           and Harris Trust and Savings Bank (incorporated by reference to
           Exhibit 1 to the Company's Registration Statement on Form 8-A, filed
           December 26, 1995).

     5     Opinion of counsel as to legality of shares of Common Stock being
           offered (including consent).

    15     Acknowledgment of KPMG Peat Marwick LLP Regarding Independent 
           Auditors' Review Report.

    23.1   Consent of KPMG Peat Marwick LLP.

    23.2   Consent of Katten Muchin & Zavis (included in their opinion filed as
           Exhibit 5 herein).

    24     Power of Attorney (included on the signature page of this 
           Registration Statement).

Item 9.  Undertakings.

     1.   The Company hereby undertakes:

          (a) To file, during any period in which offers or sales are being
     made, a post-effective amendment to this Registration Statement:

                    (i) To include any prospectus required by Section 10(a)(3)
          of the Securities Act of 1933;

                    (ii) To reflect in the prospectus any facts or events
          arising after the effective date of the Registration Statement (or the
          most recent post-effective amendment thereof) which, individually, or
          in the aggregate, represent a fundamental change in the information
          set forth in the Registration Statement.  Notwithstanding the
          foregoing, any increase or decrease in volume of securities offered
          (if the total dollar value of securities offered would not exceed that
          which was registered) and any deviation from the low or high end of
          the estimated maximum offering range may be reflected in the form of
          prospectus filed with the Commission pursuant to Rule 424(b) if, in
          the aggregate, the changes in volume and price represent no more than
          a 20 percent change in the maximum aggregate offering price set forth
          in the "Calculation of Registration Fee" table in the effective
          registration statement;

                    (iii) To include any material information with respect to
          the plan of distribution not previously disclosed in the Registration
          Statement or any material change to such information in the
          Registration Statement;

     provided, however, that paragraphs (a)(i) and (a)(ii) do not apply if the
     information required to be included in a post-effective amendment by those
     paragraphs is contained in periodic reports filed with or furnished to the
     Commission by the Company pursuant to Section 13 or Section 15(d) of the
     Exchange Act that are incorporated by reference in the Registration
     Statement.

                                       5
(b) That, for the purpose of determining any liability under the
     Securities Act of 1933, each such post-effective amendment shall be deemed
     to be a new registration statement relating to the securities offered
     therein, and the offering of such securities at that time shall be deemed
     to be the initial bona fide offering thereof.

          (c) To remove from registration by means of a post-effective amendment
     any of the securities being registered which remain unsold at the
     termination of the offering.

     2.   The Company hereby undertakes that, for the purpose of determining any
liability under the Securities Act of 1933, each filing of the Company's annual
report pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the Registration Statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     3.   Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Company and affiliated companies pursuant to the provisions
described in Item 6 above, or otherwise, the Company has been informed that in
the opinion of the Commission such indemnification is against public policy as
expressed in the Securities Act of 1933 and is therefore unenforceable.  In the
event that a claim for indemnification against such liabilities (other than the
payment by the Company of expenses incurred or paid by a director, officer or
controlling person of the Company in the successful defense of any action, suit
or proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Company will, unless in the
opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act of 1933 and will be governed by the final adjudication of such issue.

                                       6
SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Company
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Oakbrook Terrace, State of Illinois, on this 18th day
of June, 1998.

                              PLATINUM technology, inc.

                              By:   /s/  ANDREW J. FILIPOWSKI
                                    -------------------------------------
                                    Andrew J. Filipowski
                                    President and Chief Executive Officer

                               POWER OF ATTORNEY

     Each person whose signature appears below hereby constitutes and appoints
Andrew J. Filipowski, Michael P. Cullinane, Larry S. Freedman and Matthew S.
Brown, and each of them, his true and lawful attorneys-in-fact and agents, with
full power of substitution, to sign on his behalf, individually and in each
capacity stated below, all amendments and post-effective amendments to this
Registration Statement on Form S-8 and to file the same, with all exhibits
thereto and any other documents in connection therewith, with the Securities and
Exchange Commission under the Securities Act of 1933, granting unto said
attorneys-in-fact and agents full power and authority to do and perform each and
every act and thing requisite and necessary to be done in and about the
premises, as fully and to all intents and purposes as each might or could do in
person, hereby ratifying and confirming each act that said attorneys-in-fact and
agents may lawfully do or cause to be done by virtue thereof.

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on this 18th day of June, 1998.
Signature                                             Title
             ---------                                             -----
/s/ ANDREW J. FILIPOWSKI             President, Chief Executive Officer
-----------------------------------  (Principal Executive Officer) and a
Andrew J. Filipowski                 Director
                                                                        
/s/ MICHAEL P. CULLINANE             Executive Vice President, Chief Financial
-----------------------------------  Officer (Principal Financial and Accounting
Michael P. Cullinane                 Officer) and a Director
                                   
/s/ PAUL L. HUMENANSKY               Executive Vice President, Chief Operations
-----------------------------------  Officer and a Director
Paul L. Humenansky                  

/s/ JAMES E. COWIE                   Director
-----------------------------------
James E. Cowie

/s/ STEVEN D. DEVICK                 Director
-----------------------------------
Steven D. Devick

/s/ ARTHUR P. FRIGO                  Director
-----------------------------------
Arthur P. Frigo

                                     Director
-----------------------------------
Gian Fulgoni
7
Exhibit                           Description of Exhibit
 Number                            ----------------------
 ------

   4.5      Form of Mastering, Inc. 1998 Non-Qualified Stock Option Agreement
            for Employees.

   4.6      Form of Stock Option Agreement under the Mastering, Inc. Amended and
            Restated 1995 Executive Stock Option Plan.

   4.7      Form of Employee Stock Option Agreement under the Mastering, Inc.
            Amended and Restated 1995 Employee Stock Option Plan.

   4.8      Logic Works, Inc. 1995 Stock Option/Stock Issuance Plan (the "Logic
            Plan").

   4.11     LBMS Executive Share Option Scheme (the "LBMS Option Scheme").

   4.12     LBMS 1996 Equity Incentive Plan (the "LBMS Incentive Plan").

   4.13     Vivid Publishing, Inc. 1997 Stock Option Plan.

   4.14     Vivid Publishing, Inc. 1996 Stock Option Plan.

   4.15     Form of Stock Option Agreement under the Vivid Publishing, Inc. 1997
            Stock Option Plan.

   4.16     Form of Stock Option Agreement under the Vivid Publishing, Inc.
            1996 Stock Option Plan.

   5        Opinion of counsel as to legality of shares of Common Stock being
            offered (including consent).

  15        Acknowledgement of KPMG Peat Marwick LLP Regarding Independent
            Auditors' Review Report.

  23.1      Consent of KPMG Peat Marwick LLP with respect to the Company's
            financial statements.

  23.2      Consent of Katten Muchin & Zavis (included in their opinion filed as
            Exhibit 5 herein).

  24        Power of Attorney (included on the signature page of this
            Registration Statement).

                                       8