You might want to look at Leo: http://webpages.charter.net/edreamleo/front.html http://webpages.charter.net/edreamleo/front.html In particular, you'll be inter

You might want to look at Leo: http://webpages.charter.net/edreamleo/front.html http://webpages.charter.net/edreamleo/front.html In particular, you'll be interested in the @shadow file type, which keeps two versions of a file, one with the "sentinels" marking the structure and one without. Warning: in my experience, the "sentinels" are prejudiced against collaboration. Either you put the version with sentinels into Git/Hg/Bzr and the merge of changes made by two separate parties is more likely than otherwise to create corrupt files, or you put the version without sentinels under version control, and then your collaborators lose the benefit of the structure or anything else that has been omitted.