They're all derived from the original source code of SimCity from Maxis, that I ported to Unix for DUX Software starting in 1991 (see http://art.net/~hopkins/Don/hyperlook/SimCity.README and http://art.net/~hopkins/Don/simcity/simcity-announcement.htm... ), and which was donated by EA to the OLPC project under a modified version of the GPL V3 license, with the condition that the name "SimCity" only be used for versions of the game that have been reviewed and approved by EA QA:
2.1 Modification. EA hereby grants to OLPC a non-exclusive, non-transferable, non-sub licensable, non-assignable, revocable right and license to modify the Original SimCity as provided by EA for the sole purpose of producing a version of the Original SimCity for distribution on laptops provided through the OLPC Program pursuant to the specifications set forth in Exhibit A ("OLPC SimCity"). All right, title and interest in OLPC SimCity and any interim modifications shall belong solely to EA. OLPC SimCity, and any subsequent versions, will not be distributed by OLPC unless the software meets the requirements set forth in Exhibit A. For the avoidance of doubt, nothing contained in this Agreement shall be deemed to limit or restrict EA’s right to use, modify, sell, distribute or license the Original SimCity in any other manner as EA so desires.
EXHIBIT A

Territory: Worldwide
Original SimCity Code: Title: SimCity (published in or about 1990)
Format: Unix Platform
Deliverable Items: EA will deliver to OLPC the following materials on or shortly after the Effective Date:
1. Source code for the Unix port version of the Original SimCity.
2. Any EA Documentation that EA deems necessary.
General Software Requirements: OLPC agrees that the OLPC SimCity will not be approved by EA for distribution under Section 2.2 of this Agreement, until the OLPC SimCity meets the following general software requirements:
1. EA’s QA team is unable to crash the game in sixteen (16) man-hours of play-time.
2. EA’s QA team is unable to find images/language that is deemed inappropriate to achieve an “E” rating by the ESRB standard.
3. No use of any EA Trademarks that would reflect negatively upon the established reputation of EA.
4. Add copyright/license information to each source file to reflect the proper licensing.
Specific Software Requirements: OLPC agrees that the OLPC SimCity will not be approved by EA for distribution under Section 2.2 of this Agreement, until the OLPC SimCity meets the following specific software requirements
1. The Air Crash Disaster is removed from the game.
2. EA approved splash screen is shown before the start of the game.
3. Simplify the Main Menu with EA provided GUI elements.
4. All text in the game must be legible.
5. Game audio must work.
6. Remove all attempted multi-player features.
7. SimCity Should be properly integrated to the XO’s GUI
8. Code for the EA approved splash screen is not included in the source code to be distributed with the OLPC SimCity executable.
https://code.google.com/p/micropolis/wiki/License
This is from section 2.1 of contract between EA and OLPC:
http://donhopkins.com/home/micropolis/olpc-ea-contract.pdf
2.1 Modification. EA hereby grants to OLPC a non-exclusive, non-transferable, non-sub licensable, non-assignable, revocable right and license to modify the Original SimCity as provided by EA for the sole purpose of producing a version of the Original SimCity for distribution on laptops provided through the OLPC Program pursuant to the specifications set forth in Exhibit A ("OLPC SimCity"). All right, title and interest in OLPC SimCity and any interim modifications shall belong solely to EA. OLPC SimCity, and any subsequent versions, will not be distributed by OLPC unless the software meets the requirements set forth in Exhibit A. For the avoidance of doubt, nothing contained in this Agreement shall be deemed to limit or restrict EA’s right to use, modify, sell, distribute or license the Original SimCity in any other manner as EA so desires.
EXHIBIT A  Territory: Worldwide
Original SimCity Code: Title: SimCity (published in or about 1990)
Format: Unix Platform
Deliverable Items: EA will deliver to OLPC the following materials on or shortly after the Effective Date:
1. Source code for the Unix port version of the Original SimCity.
2. Any EA Documentation that EA deems necessary.
General Software Requirements: OLPC agrees that the OLPC SimCity will not be approved by EA for distribution under Section 2.2 of this Agreement, until the OLPC SimCity meets the following general software requirements:
1. EA’s QA team is unable to crash the game in sixteen (16) man-hours of play-time.
2. EA’s QA team is unable to find images/language that is deemed inappropriate to achieve an “E” rating by the ESRB standard.
3. No use of any EA Trademarks that would reflect negatively upon the established reputation of EA.
4. Add copyright/license information to each source file to reflect the proper licensing. Specific Software Requirements: OLPC agrees that the OLPC SimCity will not be approved by EA for distribution under Section 2.2 of this Agreement, until the OLPC SimCity meets the following specific software requirements
1. The Air Crash Disaster is removed from the game.
2. EA approved splash screen is shown before the start of the game.
3. Simplify the Main Menu with EA provided GUI elements.
4. All text in the game must be legible.
5. Game audio must work.
6. Remove all attempted multi-player features.
7. SimCity Should be properly integrated to the XO’s GUI
8. Code for the EA approved splash screen is not included in the source code to be distributed with the OLPC SimCity executable.