BitTorrent is a peer-to-peer file sharing protocol  and a Free Torrent Software used for distributing large amounts of data. BitTorrent has been one of the most common protocols for transferring large files over the last few years.

Miranda IM  is one of the most flexible Free Windows IM Client and messaging  application, designed for the Microsoft Windows operating system. It  is distributed under the General Public License.

 POPFile is a powerful, cross platform email classification POP and NNTP proxy, that you can use to filter spam efficiently and categorize good mail automatically. You can Automatically Sort Web Emails with Free POPFile.   

MindTouch is a Free Open Source Collaborative Platform and transforms your business with a new class of enterprise software that can hugely cuts costs, increases revenue, and provides better transparency within the organization.

Zimbra is an Ajax-based Free Cross Platform Enterprise Email Collaboration Software that integrates email, contacts, shared calendar, instant message, documents with sharing capabilities, advanced search and VoIP into a browser-based interface. The free enterprise email software is cross platform and is available for several distributions of Linux® and Mac OS® X and uses industry standard [...]