Twitter jilts Ruby for Scala

"For this sort of heavy lifting, languages like Java and C++ may be as fast as Scala. But Payne wants more than speed. He prefers Scala because it combines functional and object-oriented techniques. 'Functions are objects, and objects are functions,' he said. 'Scala asks can you have the best of these two worlds together? And you can.'

But he also prefers Scala because it's, well, beautiful. 'It's a fuzzy thing. But we like writing beautiful code, code that you're proud of, code that you can show to non-programmers and they get it.'

When Twitter made the Scala switch, it wasn't using Java Virtual Machines (JVMs). But, Payne argues, the language is that much more attractive if you're already running Java.

'The biggest selling point for certain organizations is that Scala is 100 per cent compatible with your existing JVM code. There's no wrappers. There's no bullshit. You just load up your JVM code and call in to it, and there's no performance penalty. If you have a big investment in Java infrastructure, Scala is the ideal language.'"