Javascript
My contribution to the world of Javascript is the jsxmlRPC library that allows you to use XML-RPC webservices from Javascript applications completely transparently, just as though they were native Javascript functions.
I wrote it in order to never ever have to write any Javascript again. All you need to do is provide some XML-RPC webservices and tell your friendly webdesigner that you have some new Javascript functions for them. Webdesigners love Javascript.