I am currently implementing an ontology of the developmental stages of an organism (Sea Lice in this case, but it doesn't really matter). I would like to have your recommendation on a good and user friendly editor for biological or biomedical ontologies (written in OBO or OWL). It should include syntax support for the language of choice, best with graph representation and node editing. In principle it should be like OBOedit but with a usable interface (the UI of oboedit is utterly horrible imho and sometimes it seems to mess with my obo graphs). So don't recommend OBOedit unless you have written it, or can confirm that you use it on a daily basis to write ontologies xD
Currently I have the impression that any text editor would be more efficient, but could there be an editor with syntax highlighting at least? I promise to seriously spend time on each of your suggestions and that I will use the highest ranked answer in my project (or at least try hard)