This is a Firefox plugin based on the SA-REST Specification.
In a nutshell SA-REST is a poshformat to add additional meta-data to (but not limited to) REST [REST] API descriptions in HTML or XHTML. Meta-data from various models such an ontology, taxonomy or a tag cloud can be embedded into the documents. This embedded meta-data permits various enhancements, such as improve search, facilitate data mediation and easier integration of services.
The annotator has two versions. The generic version and the NCBO version (a.k.a Kino version).