Sipcat is a software IP telephony system that helps businesses increase productivity and reduce telecommunication costs. It allows you to start running your own voice over IP PBX in a matter of minutes. It contains a complete Linux distribution, including Asterisk and all required 3rd party software.
Callweaver is a community driven software PBX project. The most important differences between Callweaver and Asterisk are built-in STUN support, the use of SpanDSP for better codecs and full T.38 fax over IP support, Sqlite instead of Berkeley DB, universal jitterbuffer, POSIX timers to avoid Zaptel timing dependencies, greater speed, more efficient dialplan execution, and greater stability.
cupsfax is a set of two scripts to integrate a HylaFAX fax server into the CUPS printing system. To send a fax, the user prints it to the designated printer queue. He will then receive email with a link to a Web form. In this Web form, the user may enter additional parameters (most importantly the receiving fax number). This way, there are no additional conditions on what can be printed, like fax numbers embedded into the file or job name. This can also be fully integrated into a Wamba/CUPS configuration, enabling Windows clients to send arbitrary documents as faxes. It also gives the full power of the CUPS print processing pipeline to sending faxes, and makes it possible to specify additional faxing options.
GROUP-E is collaboration software which integrates groupware, project management, and business server on one platform. The solution is based on a LAMP architecture (Linux, Apache, MySQL, PHP). GROUP-E offers project management, transparent Samba (file server) integration, integration of Cyrus IMAP server with administration and personal SIEVE filters, support for SyncML 1.0, LDAP-based user management with single sign-on authentication, and LDAP contact databases. GROUP-E also provides ActiveSync for synchronization.