Thrive uses C++ and Angelscript. (The wiki has a list of sites to help learn both) As for what would be considered an ‘adequate skill’, the game is entirely open source. You can just check the code and the issues, and check if you can solve one or more of the open issues. If you can, you’re good enough that you can help out, and it would be great if you joined. (Programmers are currently the biggest bottleneck in Thrive’s development, so even if you can’t do a whole lot it’d still be helpful to work as a lowly bugfixer for smaller stuff and the like)