OpenRC is a modified version of the ftc_app Software Development Kit (SDK), maintained by members of the OpenFTC community. The goal of OpenRC is to improve the development experience for teams, while providing a quick-and-easy path to install a competition-legal version of the app. See our page on competition legality.
In addition to the normal version of OpenRC, we also have a Turbo version. Both versions are significantly faster to build than the official app (as of version 3.6), but the Turbo version takes the speed improvement much further, and completely strips out the Blocks and OnBotJava features, that most Android Studio users don’t use.
When a new release of the official SDK comes out, both OpenRC and OpenRC-turbo will be updated to it within a week.