Majordomo Web API
Did you ever want to sync your Majordomo mailing list with another address database? Or make it easy for users to unsubscribe using a web interface? Then you will have noticed that Majordomo only offers you a mail interface or an admin tool that you have install on your mailserver. So what if you don't have access to the mailserver?
Then I got the solution for you: introducing Majordomo Web API
I needed to sync an address database in eGroupware with different Majordomo mailing lists (every night). I did this by building a small API that looks like a normal asynchronous API - just with the difference that in be background a mail request to Majordomo is sent and the results are retrieved from an IMAP or POP3 account.
Get the code, or look at egroupware_update_mailinglists.php script for an example. It should be easy to build a modern AJAX web interface on top of the JSON-based RPC interface.
As it always is, our mailing list provider switched from Majordomo to Mailman only a couple weeks after I finished the scripts. So the work didn't really pay off, but I hope it's useful to somebody out there.