Derelict Games is at heart a collaborative open source project, and as such welcomes community contributions. You're welcome to send new art, one-off patches, content suggestions, and good ideas via the usual bug reporting instructions outlined above.
Those wishing to do more substantial code contributions may wish to look at our repository on gitlab. The file doc/getting_started.txt suggests easy areas to work on first. Send us a pull request if you have something cool to include.
If you'd like to participate more deeply and directly, that's great! We've got a "2 contributions" rule as an entry requirement, so get a couple patches accepted, or thumbs up from the art crew on a couple pieces of art or sound or whatnot. Then, just ask one of the current team and we'll get you hooked in!
If you would like to work on our Spacebase DF9 fork, join us on Freenode IRC in channel #spacebase-df9, or join the mailing list at https://groups.google.com/forum/#!forum/spacebase-df9
What skills do you need? Most of the code is written in Lua, and as it's a big established codebase it overall requires Patience and Persistence. Artwork requires 3D modeling skills and a good eye for design, texturing is a plus; Blender is our preferred tool. Content production requires a sense of humor and experience with standard Sci Fi tropes. Translation work requires being able to write coherently in more than one language. Packaging and porting requires depth of knowledge in how your operating system works. Even more critical are skills like, "Good teammanship," and "Having time to commit."