[evanrmurphy]

Not sure how obscure these would be here (I first learned about them on Hacker News), but I've found Backbone.js and Underscore.js to be extraordinary projects.

Links:

http://documentcloud.github.com/backbone/

http://documentcloud.github.com/underscore/

[jashkenas]

For a bit more information -- Backbone.js and Underscore.js are open source components of DocumentCloud, funded by the Knight Foundation's News Challenge, and are used to build this:

http://cl.ly/3N0Z

... and this:

http://documents.latimes.com/la-county-plastic-bag-ban/