Semantic Annotation for Diaspora Posts

Hello: after reading about a project called SALT (Semantically Annotated Latex), I decided to use a similar system to mark up my research papers. This basically involved writing a few new Latex commands which either hide or markup in some way (e.g. in color) spans of text to which semantic annotations have been applied. I then decided to integrate this into a Latex preprocessor I am working on which uses C++ and Ruby. I then thought that it would be nice to use the same system for my diaspora posts, formatting the annotated content as HTML rather than Latex. Instead of just preprocessing text before sending it to my pod server, since my preprecessor is in Ruby I’m considering trying to develop it as a feature that could be added to Diaspora; that is, a separate handler which could preprocess posts marked with a specific format. But I’d like to know whether other Semantic Annotation systems have been explored for Diaspora already. Any suggestions about where I could look? Thanks.