Knowtator is a general-purpose text annotation tool that is integrated with the Protégé knowledge representation system. Knowtator facilitates the manual creation of training and evaluation corpora for a variety of biomedical language processing tasks.
DBpedia Spotlight is a tool for annotating mentions of DBpedia resources in natural language text.
The source code is now hosted on GitHub: https://github.com/dbpedia-spotlight
The Text Annotation Environment (tae) can be used to annotate natural language text manually or automatically (UIMA Annotator) with meta information (tokens, part-of-speech, named entities, ...). Tae is based on Eclipse and IBM's UIMA.