Outgoing documents can be any format; the sendfax program uses a rule-based definition file similar to the System V /etc/magic file to deduce document types and to decide how to convert each document to a form suitable for transmission (either PostScript or TIFF/F). Automatic cover page generation is supported and users can easily tailor cover pages to their environment. A simple text-based phonebook database is supported by sendfax. Information is also provided on how to trivially setup an email to fax gateway service.
Incoming facsimile are stored in a receiving area as TIFF/F (read ``TIFF Class F'') files and may be automatically delivered by mail and/or printed. A fax server status program, faxstat, can be used to monitor the send and receive queues, as well as the state of facsimile servers.
Fax modems may be shared with outgoing data communication applications that honor the "UUCP locking protocol". These applications typically include: cu, tip, kermit, uucp, slip, and ppp. The system can also be configured so that incoming data calls cause the system to invoke the standard system getty or ttymon programs.
The software is structured around a client-server architecture. Fax modems may reside on a single machine on a network and clients can submit an outbound job from any machine that can communicate with the machine on which the modems reside. Client software is designed to be lightweight and easy to port; imaging can be offloaded to the server or done on the client. (Imaging is, however, typically done on the server because it simplifies administration.)
Clients and server communicate over a protocol which is similar to ftp and you may also use ftp or telnet to communicate to the server directly. Actually there are clients for Unix, WIN-3.x, Win95 and Mac.
An access control mechanism is included to control which users on which machines may submit jobs.
Multiple modems on a single server machine are effectively scheduled for high throughput. Broadcast faxing is well-supported through optimal imaging of transmitted documents and the effective scheduling of modem resources. Support is provided for scheduling jobs during off-peak hours based on the destination phone numbers (e.g. long distance calls may be scheduled for off-peak phone rates). An access control mechanism can be used to restrict the class of phone numbers called so that, for example, calls to emergency services such as 911 can be rejected out of hand.
The server requires a PostScript to facsimile imaging utility for useful operation (otherwise, only pre-imaged facsimile may be transmitted.) A Display PostScript-based imager is provided for IRIX 4.x- and 5.x-based systems. For other systems, a Ghostscript-based version can be built from the GNU sources.
HylaFAX is freely available under copyright in complete source form. It may be used in commercial applications in part or in whole without charge. There are binary distribution packages or other formats for several Unixes.
BTW: You should call it ``HylaFAX'' and not something like Hylafax, HYLAFAX, HYLAFax, HYLAfax, HyLaFAX, HylaFaX, HylaFax, Hylafax, hylaFAX, hylaFAx, hylaFax, hylafax ...