Собственно, сабж!
Фейсбук пишет свой сервер Mercurial на расте: https://groups.google.com/forum/m/#!topic/mozilla.dev.version-control/nh4fITF...
* Facebook is writing a Mercurial server in Rust. It will be distributed and will support pluggable key-value stores for storage (meaning that we could move hg.mozilla.org to be backed by Amazon S3 or some such). The primary author also has aspirations for supporting the Git wire protocol on the server and enabling sub-directories to be `git clone`d independently of a large repo. This means you could use Mercurial to back your monorepo while still providing the illusion of multiple «sub-repos» to Mercurial or Git clients. The author is also interested in things like GraphQL to query repo data. Facebook engineers are crazy... in a good way.