This feature would massively help guilds and friends. It would also lead to more people using Ajour, for sure.

1. Have an "Export" button which generates a YML file, with a format that contains "addon name", "addon id (curse id or similar)", "source" (curse, wowinterface, github url, etc), "channel" (release, beta etc), and flavor (retail, tbc, etc).
2. Have an "Import" button, edit: Moved import ideas to a comment: [Feature] Exporting "My Library" as YML, and importing on another computer #659 (comment)

This would be a major feature to implement, but hey, a man can dream.