Most of the posts we make about software is about their latest versions and newest builds. How about older versions? You may ask why anyone would want to use an older version while more advanced newer builds are available. I could tell you a dozen reasons; bloated software, incompatibilities, i-hate-the-new-interface, integration of junk and the list goes on. Luckily, there is a site out there which hosts older versions of popular apps; OldVersion.com.
Currently, OldVersion.com has 2479 versions of 182 software in their database.
Screenshot: Old versions available for MSN Messenger
All downloads are direct HTTP downloads hosted at download.oldversion.com. I got excellent speeds downloading a few software from there and their server seems quite fast.
[Click Here] to visit OldVersion.com
P.S.- You can find older versions of software on FileHippo.com as well but it does not index some of the oldest versions most of the time.