SharePoint features are an incredibly useful way to deploy chunks of functionality to web sites. Although they can be difficult to grok at first, once you do, they make a lot of sense! Scot Hillier, a very well known SharePoint expert has begun a CodePlex project titled SharePoint Features, which aims to provide some extra functionality to SharePoint. He’s kicked off the project by contributing some really cool stuff, including a Debugging Feature, a Log Viewer Feature, and a Theme Changer feature. He’s also got loads more up there! Have a favorite feature you’ve built? Contribute!
I haven’t checked out what license they are released under, but they’re worth checking out!