SimCity 64 was released for Nintendo 64DD, the Japan-only Nintendo 64 add-on. Cancelled NES version A version for the Nintendo Entertainment System (NES) was announced alongside the SNES version and had been showcased at the 1991 Consumer Electronics Show, but the NES version was never properly released. However, prototype cartridges for the NES version were discovered in 2017, and one copy was obtained by video game preservationist Frank Cifaldi, who extensively documented its features compared to the original personal computer game and the SNES version. It featured a completely different soundtrack (also composed by Oka) from that of the SNES version; besides Metropolis Theme, a composition that Oka herself considers one of her best works. Micropolis In January 2008, the SimCity source code was released as free software under the GPL-3.0-or-later license, renamed to Micropolis (the original working title) for trademark reasons, and developed by Don Hopkins. The release of the source code was motivated by the One Laptop Per Child program. The Micropolis source code has been translated to C++, integrated with Python and interfaced with both GTK+ and OpenLaszlo. In 2008, Maxis established an online browser-based version of SimCity. A second browser-based version was later released under the name Micropolis. In 2013, a browser-based version was released, ported using JavaScript and HTML5, as micropolisJS. Since Micropolis is licensed under the GPL-3.0-or-later, users can do anything they want with it that conforms with the GPL-3.0-or-laterthe only restriction is that they cannot call it "SimCity" (along with a few other limitations to protect EA's trademarks). This allows other, differently named projects to be forked from the Micropolis source code. Improvements to the open-source code base that merit EA's approval may be incorporated into the official "OLPC SimCity" source code, to be distributed with the OLPC under the trademarked name OLPC SimCity, but only after it has been reviewed and approved by EA. Comparison of different versions SimCity Classic is available for Palm OS and on the SimCity.com website as Classic Live. It was also released by Atelier Software for the Psion 5 handheld computer, and mobile phones in 2006. The July 2005 issue of Nintendo Power stated that a development cartridge of SimCity for the NES was found at Nintendo headquarters. Never released, it is reportedly the only one in existence. Additionally a terrain editor and architecture disks were available with tileset graphics for settings of Ancient Asia, Medieval, Wild