We have switched from PHP to Scala just recently because we found PHP was lacking a bunch of features we needed. I was not paying much attention to the trends in the PHP world since, so I was very curious how Facebook manages to go on with PHP without all those shiny toys we were missing. They don't. They created the Hack language that is backward compatible with PHP and allows them to add new features like type checks, asynchronous method calls, multipel collection types, lambdas, etc. It looks pretty awesome.

They are also, very interestingly, doing a bunch of stuff quite different than the current trends would dictate, for example they have a monolithic codebase (56GB git repo) and they seem to like it.