Pair.io: on demand cloud pair programming environments (opens in new tab)

Some projects are self-contained, and for those you don't need any supporting infrastructure outside the runtime of your language. But once you start dealing with _systems_ where it's very particular about the specific version/configuration of the database or message queueing system, it's much less error-prone to have that automated. For that you need control of a whole machine, virtual or not.

I wrote a blog post about a similar approach applied to local VMs: http://technomancy.us/150

A server is spun up and credentials given to all the invited users. Once a user logs in they can connect to a common tmux server and share a text-editor/cli/etc.

that I don't understand either. You can do the same thing on your own machine, just add a user and tmux there, where you have the current code base up and running.

Project-specific configs can be committed to a repo to override the default configuration.

So is the message you get if you try authenticating with GitHub without being in the private alpha.