LibreCAD code is hosted by Github where releases 2 and 3 are developed together. SourceForge is the former code repository but importantly it provides an autonomous Windows build server with scripts for uploading nightly builds.
LibreCAD is mainly coded with C++. There are also some nice-to-have skills improving productivity:
If you are a developer, outstanding in C++, or a beginner we can use all the help. With a bit of determination, the IRC channel, Zulip chat and the Libre-CAD-dev mailing list, we can help you getting started and making progress.
A good starting point for developers is the LibreCAD Developer’s Wiki on GitHub. You will find information on developing requirements, building from source, Git and Github usage and LibreCAD font format.