Well, I'd understand your concerns if you asked about Haskell or Erlang for web-development. I suppose there are not so many companies who develop their web app

Well, I'd understand your concerns if you asked about Haskell or Erlang for web-development. I suppose there are not so many companies who develop their web apps in those languages and it may be just not that easy to find an appropriate position. But Java? Open http://yclist.com/ http://yclist.com/ (list of YC companies). There are enough of those who uses Java.