Rackspace recently published an infographic on the evolution of programming languages. You can click through to Rackspace to see the entire infographic – the more applicable section, in my opinion, is the overall popularity at present.
When I'm speaking with large companies, there seems to some question by the IT and development teams as to the plausibility of open source languages. While they take .NET and Java seriously, they tend to dismiss languages like Ruby on Rails and PHP. You don't have to look much further than sites like Facebook, though. Facebook is largely built on PHP.
