TornadoCookie's various projects::OpenSC5

GitHub

OpenSC5 is a reverse engineering project for SimCity (2013), also called SimCity 5. Since SimCityPak has become completely dead, this is now the only SimCity-focused program out there.

Parts of it are based on code from SimCityPak, others from other sources, and other parts are completely novel.

A major part that only OpenSC5 does is download the update files from update.prod.simcity.com. Turns out, you can get SimCity for free! (unfortunately it still looks for origin but the data files are still free)

Features as of September 2026:

• DBPF (.package) reading, writing, browsing, and searching
• Read-only support for Rdx9, PROP, and RAST files
• Research into img8, img16, img32, SWB, ER2, statefile, and SDelta files
• An EAWebKit frame which launches the updater (disabled in current build, will be scrapped)
• Ability to convert BNK and Wwriff files into .ogg files using builtin ww2ogg
• Research into the encryption of the SimCity executable and they key required to decrypt it
• Updater program which downloads the latest version from the SimCity servers

2026 for SimCity 2013

2026 has actually been a really big year for sc13. There have been many breakthroughs in modding spurred upon mostly, as it seems to me, by advancement in AI tools. For example, a reddit user managed to get native large city tiles, among other several advancements. and one chinese gentleman is making a project very similar to OpenSC5, just made quicker because its made with AI and Vue.JS instead of pain and suffering.

With all these new advancements, I believe that a new standard in SimCity modding is in order. Ideally we want something somewhat compatible with the SimCityPak workflow, based on new technologies. Ultimately, OpenSC5 needs to go in a different new direction in order to stay relevant.