TMedit is a web-based Editor for Topic Maps, an ISO standard for describing ontologies. It is a result of a project at the study group Formal Models, Logic and Programming (FLP) at the Technical University of Berlin.
Currently it supports importing of XTM files (by uploading), editing of topics and associations and exporting back to XTM again. Further it is possible to set a working scope - so that basenames etc. of topics can be shown subject to a special localization for instance.
TMedit is build using the TM4J Topic Map engine and the Apache Struts Framework. The list of developers is rather small in the moment, so if you are interested in contributing code to the project feel free to contact me (jaspo at cs.tu-berlin.de).