Native Mac Support for MSN Messenger
I've poked around in some of the Mac versions' files, and although I've found various references to the things that need to be changed, just like on the Windows versions, editing them doesn't seem to make any difference.
Some of the files I've found that look like prime targets for editing: (The .app filenames might differ, these just happen to be what I named them to identify them - I think they're probably just Microsoft Messenger.app on a fresh install)
5.1.1:
Microsoft Messenger 5.1.1.app/Contents/MacOS/Microsoft Messenger
Microsoft Messenger 5.1.1.app/SharedSupport/Microsoft Messenger Daemon.app/Contents/Microsoft Messenger Daemon
(Will add more later, but I think they're all quite similar.)
Not all doom and gloom however, I haven't had zero progress, because Messenger for Mac 3.0.0 only needs the MSNP server, so I was able to twiddle my hosts file to point it at Escargot - and it works...
If you want to test this, add the following line to /etc/hosts
35.185.201.91 messenger.hotmail.com
I don't yet know how late a version of OSX that'll run on, because I've only got Tiger to test PowerPC clients on. At a push it might work on Snow Leopard if you manually install Rosetta, but I can't verify that.
So, small victories. I'll continue poking around to see if I can figure out where it's pulling these versions are pulling their domain names from.