In mature platforms most specific problems have official solutions either in the core libraries or in the extended standard library set (for java, which I currently use, that would be Sun + Apache).

Also from building a first draft (could take less than a day) to a professional solution you have to pass two big hurdles: feature set and performance. Each of them done properly can take easily more then a week.

I do like the idea of using the libraries of different platforms. Wrappers are much easy to write, and a mechanism for using java classes from arc/lisp would solve a world of problems. Unfortunately I can't imagine it being done without a big performance hit.