Erlang the language, that is.
Erlang is a declarative, concurrent language that has many desirable properties and mechanisms for doing what utility computing requires. Amazon SimpleDB is built on Erlang, IMDB (also owned by Amazon) is switching from Perl to Erlang, and Google Gears is using Erlang-style concurrency, to name a few bourgeoning applications using it. Some of its attributes are shown off in this amusing movie. No, that's not a younger John Cleese, Graham Chapman, et al., doing the presentations and yes, that is a picture of Agner Erlang; the father of queueing theory.
Apparently, these blokes, some of whom are the original developers, are from Ellemtel, a subsidiary of Ericsson. Although slightly lame in production values, they the movie does demonstrate a geniune robustness in Erlang's concurrency features; well ... for telecom switches, at least.
Somewhat ironically, Erlang was released by Ericsson as open source in 1998 because an internal executive decision was made to go with "standards" instead.