Does your server need to respond to many different independent messages concurrently? Do you need to parcel these requests out to different cores or servers in various parts of the world? That's practically the definition of the hardest part of enterprise computing. Erlang, an open source language first created by scientists at Ericsson Computing Laboratory, excels at these tasks.
[ For a deeper look at today's "slacker databases," see the InfoWorld Test Center review "NoSQL databases break all the old rules." ]
CouchDB is just the beginning. A number of project managers dealing with "big data" are building systems for storing large volumes of data in a scalable way. Hibari, an open source project from Gemini Mobile, offers consistent, scalable clusters to store key-value pairs that repair themselves after failure. The functional structure makes it easier to create big applications that juggle multiple connections efficiently.
Programming languages on the rise: Cobol
It may not be fair to call Cobol a niche language as it was once the dominant language in the enterprise. Grace Murray Hopper, famous for finding the first bug in the early mainframes, helped create the language in 1959 and it's been enhanced hundreds of times since. Cobol jockeys today get to play with object-oriented extensions, self-modifying code, and practically every other gimmick.
That never earned it much respect in some circles. Or as famous academic Edsger Dijkstra put it: "The use of Cobol cripples the mind; its teaching should, therefore, be regarded as a criminal offense." The folks in mainframe shops everywhere ignored this note and soldiered on. IBM calls one of the latest releases "Enterprise Cobol 4.2," but it could as easily be numbered 147.2 or maybe even 588.3. Cobol programmers like the syntax that's more like a natural language with actual nouns and verbs that form clauses and sentences -- a technique that might call Ruby to mind.
While fewer schools are teaching new programmers Cobol, the language is far from dying, with many corporations continuing to invest in their Cobol stacks. A recent search of Dice.com showed 580 jobs mentioning Cobol and 1,070 mentioning Ruby. The bulk of the jobs seemed to involve counting money ("asset management") and counting doctor's visits ("Health IT"). While these are some of the same areas that first adopted computers for back-office processing, the work still needs to be done.
Versions of the languages run on JVMs and .Net virtual machines making it possible to migrate code stacks away from mainframes to Linux boxes. Programmers who want to use a more modern IDE can search for plug-ins to Eclipse, a project that is gaining new support.