WURFL is an open-source project and it has been running for about 5 years now. Initially it was a common effort of a few developers around Europe willing to share some information and save some money from buying every phone on the market.
Later it turned into a very valuable information source for anyone in the mobile space from anywhere in the world.
Today is the de-facto standard for anyone that wants to build a mobile solution in-house.
How much does WURFL cost? It is still entirely free. The main XML includes devices for 1999 to 2006 (and 2007 soon!). The free libraries range from PHP to Java, Ruby, python, .NET, etc. Basically any well known programming and scripting language.
What do you need to start? An idea and One or more programmers to turn your idea into something real using the tools that WURFL provides.
It looks like there’s someone with an idea and looking for an experienced programmer: J. Edgar and associates, a recruitment company. I just found a post about a job opportunity in which WURFL is a requirement!
The yearly payment is not bad at all, 90.000+ dollars. It is not clear to me if it’s US dollars or Canadian. Anyway it seems like WURFL programmers are very well considered.