Language Documentation
OpenMud uses the Dream Maker Programming Languages to define the logic in your game. Users coming from Byond may be familiar with this programming language. The DreamMaker language is thoroughly documented on the BYOND website here (guide) and here (reference)
Note that while OpenMud does aim to fully implement the Dream Maker programming language, there may be some variations in the framework (APIs, or game behaviours.) Thus, we do aim to eventually provide a comprehensive guide here for the Dream Maker programming language and API / Framework independant of Byond.
If you find OpenMud is missing features you would like, please create an issue so that a developer can address the request and consider including it in OpenMud. Alternatively, the OpenMud framework is easily extensible and you may even try creating the feature yourself.