It would be very useful if the source code for addons hosted on AMO was indexed using LXR/OpenGrok/etc. The success of the Code Snippets on MDC highlights that ext devs are looking for ways to solve common problems. The single largest repository of these "solutions" is AMO. Not sure what this would mean from a licensing point-of-view, but perhaps one checkbox for devs adding their extension would be to have it indexed. Retroactively you could go based on licenses. Mark Finkle pointed out that http://lxr.mozdev.org/ exists, but it is not working as I write this (searches redirect to the main mozdev page). I'm constantly telling students to look at extensions on AMO for examples of what they are trying to do. Having access to searchable code would be much better.

This can be done outside of the AMO system, and probably should be. If there's data that such an indexing service needs from the AMO database, we should add it to the upcoming API, but the files in question are all easily fetchable, and decoupling here would be a ton easier on everyone.

How would we know if we are legally allowed to index such source code, though? As far as I know not all the add-ons on AMO are 'open' as such :-(.