And, you'll be increasingly coming across Mercurial, since it's been adopted by Mozilla four years ago, by Google in 2009, and is preferred by Windows, Python, and Django developers. (89% of our respondents have heard of GitHub and 62% of its Mercurial sibling BitBucket.)
"Adopted by Google" here seems a bit disingenuous; they offer Mercurial as an option for developers that want to host their OSS projects with Google, it isn't as if Google's in-house source control has moved to Mercurial.
I've heard that the server it runs on is the most powerful machine Google owns. Perforce can't be distributed and has to keep track of all the files that are opened by every user (p4 edit). Must be quite a beast.
When I last used Perforce about five years ago, it did allow for read-only proxies to help reduce the load on the main server, particularly in environments where the developers were geographically dispersed. It worked quite well.
And when I was there a few years ago, it was also the slowest service with the most downtime. grumblegrumble* I hope that they have addressed that by now.
Nope, it's still basically that way. Well, Mondrian seems to have more downtime, but a lot of Mondrian outages are really Perforce outages that propagate down the stack.
"Adopted by Google" here seems a bit disingenuous; they offer Mercurial as an option for developers that want to host their OSS projects with Google, it isn't as if Google's in-house source control has moved to Mercurial.