vtiger CRM is 100% Open Source Customer Relationship Management
solution built over LAMP/WAMP stack and other third-party open source
packages.

vtiger CRM software can be installed in Windows
NT/2000/XP/2003 and different types Unix/Linux-based distributions,
such as RedHat 7.2/8.0/9.0, Debian 3.0, SuSe 9.0, Fedora Core 3.0,
Mandrake 10.0, Mac OS, and FreeBSD.