At Amahi we use git (see our [https://github.com/amahi gitGithub repo] ) for our version management and the technologies we have ended up using are Ruby, Ruby on Rails, PHP, Linux system internal technologies like system services, configuration areas, web server virtualhosts, databases, DNS, etc., etc.
We're looking for students who are interested in both current technologies like RoR, as well as next generation technologies we are using or could be using, like Go (we use it for streaming to our mobile apps), Node.js, javascript frameworks for user interaction, visualization or server services, [https://github.com/amahi/spdy SPDY], etc. etc.