Wikipedia
Cyn.in is an open source enterprise collaborative software built on top of Plone a content management system written in the Python programming language which is a layer above Zope. Cyn.in is developed by Cynapse a company founded by Apurva Roy Choudhury and Dhiraj Gupta which is based in India. Cyn.in enables its users to store, retrieve and organize files and rich content in a collaborative, multiuser environment.
Cyn.in comes in three flavors. Cyn.in Community Edition is released under the GNU General Public License version 3 based on open standards and is completely "free" to use. Cyn.in Enterprise Editions are commercially supported, certified and tested by Cynapse. The on-premises appliance is designed towards businesses who want to install the software on their infrastructure behind their firewall. With the On-Demand Service, Cynapse hosts the software for businesses to use, in secure cloud servers.