Development:DIRTSAND
DIRTSAND is developed by H'uru on Github. If you wish to contribute, you can fork the repository and submit pull requests with your modifications. DIRTSAND is currently quite feature complete; unavailable features such as Heek are due to intentional design decisions.
Note: development of DIRTSAND is currently on indefinite hold as development of Wondruss is underway, the latter being set to eventually replace DIRTSAND.
Building
DIRTSAND can be built from source for Linux (and possibly other *nix) OSes. Follow the getting started guide to build DIRTSAND for your system. You'll need Git to fetch the sources.
Contributing
The process for contributing to DIRTSAND is essentially the same as for Plasma.
Roadmap
DIRTSAND is set to be superseded by Wondruss eventually; whether DIRTSAND will continue to be developed remains to be seen, as it is mostly feature-complete right now. For up-to-date information, consult the Open Source Task List.