In this paper we present GitDOX, an open source online, schema aware XML annotation interface linked to Natural Language Processing tools, which uses the online GitHub platform as a backend for version controlled electronic corpus development. We apply this platform to the use case of transcribing and annotating Coptic manuscript data from first millennium Egypt, in a collaborative team. The architecture of the tool is meant to be generic and extensible, supporting an unbounded range of annotation schemes, while being simple to use for annotators without extensive training in computational tools or version control software.