Deus Ex was built on the Unreal Engine, which already had an active community of modders.[70] In September 2000, Eidos Interactive and Ion Storm announced in a press release that they would be releasing the software development kit (SDK), which included all the tools used to create the original game.[71] Several team members, as well as project director Warren Spector, stated that they were "really looking forward to seeing what [the community] does with our tools".[72] The kit was released on September 22, 2000,[73] and soon gathered community interest, followed by the release of tutorials, small mods, up to announcements of large mods and conversions.[70] While Ion Storm did not hugely alter the engine's rendering and core functionality, they introduced role-playing elements.[70]