I am trying to set up a page for an international musician collective where we will collaborate on a work and then post the resulting project as a freely available download to either all members of the group or open to the general public. My thought would be that the backend-- for those participating in a particular project-- would be sort of like Dropbox or any other file synchronization software or minimalist collaborative productivity suite. Once a project is finalized, it would be published to the general accessible page.

I am pretty sure this is well-traveled territory and I do not want to re-invent the wheel. However, I am not sure what the best-- and most simple-- solution is. Does anyone have recommendations?