There are a lot of changes, most of them not yet documented:
- updated to work with with CMSMS 2.x series;
- BBCode should work out of the box (may currently break compatibility with JM_BBCode module);
- added a palette of emoticons with the respective parser;
- added uploads of attachments to posts;
- templates are now separated from the settings (not yet on DM for backwards compatibility);
- and more...
This should be the last branch compatible with CMSMS 1.12.X, although updates and stability releases may be expected for sometime (at least a year from stable release but not much longer);