Wikipedia:Branching support

I would propose the addition of support for easily creating Wiki forks into MediaWiki. Let me explain how this would work:


 * 1) I set up my own database and instance of the MediaWiki software on my server...
 * 2) I download a database dump, and install it on my server, in a separate database from my main MediaWiki database...
 * 3) The MediaWiki software lets me selectively import articles from one or more database dumps installed on my server. It automatically adds an attribution link back to the original Wiki the dump came from, and marks the revision which I branched off...
 * 4) At a later date, I download and install a new, updated database dump. By clicking on any page imported from the original Wiki, it will give me a 3-way diff (ala CVS merge) between the changes I have made to the imported page, and the changes to the imported page since I imported it into my wiki...
 * 5) The original Wiki can fetch the changes my fork has made to it (either via import of a database dump or via a web service), and integrate them if it wishes...

Thus, we could create forks of Wikipedia with particular points-of-view or topic focuses (e.g. Christians could create a Christian fork with Biblical Point of View (BPOV) and a focus on Christian topics), but could regularly resynchronise between the parent Wikipedia and the forks -- useful material from the parent Wikipedia since the article import could be copied to the fork easily, and recent innovations in the fork could be copied to the parent.

Such Wikipedia forks might have some advantages over the regular Wikipedia:
 * more co-operation between members of the user community, due to share ideology
 * ability to tap sponsorship avenues not open to main Wikipedia -- for example, a Christian fork of Wikipedia could tap Christian funding sources, which would be likely to fund a Christian fork, but not the mainstream Wikipedia
 * ability to add commentary that is of only local interest, without losing ability to resync

By providing this branch-and-merge support in MediaWiki, we both make it easy for people to set up such Wikipedia forks (thereby getting the advantages of them), while at the same time mitigating some of the disadvantages, by making it easy for the changes in the fork to be merged where appropriate back into the parent, and vice versa.

Wikipedia forks would also arguably have some disadvantages:
 * would assist attempts by repressive governments to censor information
 * would encourage the formation of isolated subcommunities that are immune to truth and persuasion
 * could subvert the consensus-forming community functions of Wikipedia

See also the feature request on Bugzilla.