Maphub in a web portal for georeferencing and annotating digitized historic maps. Georeferencing transforms the map image to align with real world geographic coordinates, while the annotations are overlaps plus notes. Maphub suggests possible tags for the annotation based on its text and location; tags link to related Wikipedia articles. Once created, user-contributed annotations are shared via the Maphub Open Annotation API.
, Collaborative editing
FromThePage is free software that allows volunteers to transcribe handwritten documents on-line. It's easy to index and annotate subjects within a text using a simple, wiki-like mark-up. Users can discuss difficult writing or obscure words within a page to refine their transcription. The resulting text is hosted on the web, making documents easy to read and search.