aMSN is described as 'free open source MSN Messenger clone' and is an app in the Social & Communications category. There are more than 10 alternatives to aMSN for a variety of platforms, including Mac, Windows, Linux, Android and Online / Web-based. The best alternative is Pidgin, which is both free and Open Source. Other great apps like aMSN are Facebook Messenger (Free), Adium (Free, Open Source), Empathy (Free, Open Source) and IM+ (Freemium).
OctroTalk is an Jabber/Gtalk client with support for GTalk (GMail) audio and Video calls. OctroTalk also supports SIP calling (through a provider of your choice). Features: 1 ) Connect securely to GTalk/Jabber 2) P2P Audio/Video Calling
Escargot is a custom-written server built to recreate the older MSN Messenger server architecture, used back when Microsoft still had the servers running. The code to recreate the servers works for versions of MSN up to 8.