As platform-as-a-service providers spring up, one area that's been sorely missing is support for functional programming and actor-based programming languages. Clojure, Erlang and Haskell are popular development environments, but these programming paradigms are being left out of the PaaS stack (though yes, you can do functional programming in languages like Python).
Scala is a multiparadigm programming language famously used at companies like Twitter and Foursquare. The creator of Scala, Martin Odersky, recently launched an enterprise support company for the language. Those wanting to really dive into the language may want to check out our post on free Scala e-books.
In addition to Lift, Cloud Foundry developers will be able to use the Java framework Spring to build Scala applications.
Cloud Foundry warns that most Scala applications will need to be modified before they will work on the Cloud Foundry PaaS. You can find details in this blog post.
We heard recently from a startup that is planning to launch an Erlang PaaS. We'll of course keep you informed of further developments in the PaaS space.
Disclosure: Cloud Foundry is owned by VMware, which is a ReadWriteWeb sponsor.