HylaFAX is a fax and paging system for Unix. It supports sending facsimile, receiving facsimile, polled retrieval of facsimile, transparent shared data use of the modem and sending alpha-numeric pages. The software is structured around a client-server architecture. Fax modems may reside on a single machine on a network and clients can submit outbound jobs from any machine that can communicate with the machine on which the modems reside. An access control mechanism is included to control which users on which machines may access a server.
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.
Collax Groupware Suite is a complete collaboration, e-mail, and messaging server with Outlook MAPI support. It offers enterprise email server functions, anti-spam and anti-virus filters, GUI management, a file server for SMB, NFS, FTP, and Apple shares, backup/restore server, IM server, and fax and SMS server. The groupware offers AJAX Web mail, calendar, team calendar, contacts, and tasks, and supports ActiveSync for mobile devices. It is free for private or commercial use of up to five users.
VOCP is a complete messaging solution for voice modems, with voicemail, fax, email pager, DTMF command shell and Text-to-Speech support, 4 graphical interfaces, and a Web interface. Callers navigate the system using a touch-tone phone and may send and receive faxes, voice mail, and pager messages, listen to text/HTML email messages, or execute configured programs on the host and hear the resulting output.
The mgetty package contains an intelligent getty for allowing logins over a serial line (such as through a modem) and receiving incoming faxes. The companion program sendfax is used for sending faxes from the commandline or from other applications. The third main component is vgetty/vm which can be used with a voice-capable modem to implement an answering machine, a voice menu system, and similar things.
fax4CUPS is a very simple shell script that acts as a CUPS backend for a serial fax modem. Essentially, you print with lpr and the fax is sent. The nice thing is that you have CUPS around, and this means, for instance, that you can check whether your fax has been sent just using your favorite browser (as you would do for any other printer), even if the fax modem is really on a remote server. It supports efax, HylaFAX, mgetty-fax, and Capisuite.
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.
smbfax is a Unix server which allows you to print via Samba from a Windows client to a hylafax-controlled faxmodem on your server without any additional Win32 software for the client. It's as easy as File->Print from an application, choose the network fax printer, then check your email's INBOX. You can also view and delete jobs via the standard Windows methods.