How could we go about designing an interconnected global software repository?

Concept: A single place where every function, every bit of code is indexed, analyzed and stored in an integrated. Purpose: To index all the code there is, make function-sharing even easier and more efficient. Make application-development lightning fast. Easily string together functions in easier configurations – allowing even novice computer users to make custom applications and bring them to life quickly.

Similar concepts that are missing the integration: http://sf.net https://github.com/ http://code.google.com/

A similar project that has the integration but not the openness: http://www.wolframalpha.com others like it?
In this project, wolfram is integrating functions and relating them across each other. In what he calls a computational search engine.

This is a collaborative question/discussion. How could we piece those together?