Simon Willison’s Weblog

Is there a free/open-source software source code search engine?

My answer to Is there a free/open-source software source code search engine? on Quora

If you want to search through actual code in open source projects, GitHub search is fantastic https://github.com/search—e.g. here’s a search for all Ruby code that mentions oauth https://github.com/search?q=oaut...

If you want to find web service APIs to integrate with, Programmable Web still have the best index that I know of: http://www.programmableweb.com/apis