Furthermore the serious concern with a VCS hosting monopoly is portability, but as long as Github uses git, portability is a non issue. Cloned the repository?

Furthermore the serious concern with a VCS hosting monopoly is portability, but as long as Github uses git, portability is a non issue. Cloned the repository? You can now declare yourself the canonical source for that repo instead of Github, host it from your own machine, and let others pull directly from you. Not that you'd usually want to do that, but it's available as an option if you do. If Github closed down tomorrow, we'd lose a lot of code. If Github announced that in one year they were going to close down, then we'd only lose private repositories that no one bothered to clone. There is the issue of, well, issues. And pull requests and wikis and all that. But wikis are, as far as I know, just git repos themselves, so that's not too bad. Issues and pull requests and all of that sort of data probably has to be pulled out through the API into some format that's hopefully useful in other places. Could easily lose a lot of work here if Github went poof. Not that I think they will or that I want them to, just something that's important to consider when a service becomes a monopoly becomes critical infrastructure.