Facebook's "phabricator" is very different from OSS, to the extent that at this point probably most of what's left is terminology and architectural boundaries.

Facebook's "phabricator" is very different from OSS, to the extent that at this point probably most of what's left is terminology and architectural boundaries. The diff (PR) UI was completely rewritten; I think repo browsing too. Most of the storage got refactored to use common storage code.