It often seems that those involved in using and promoting Linux can be even more aggressive than Windows fans lately in evolving applications for it.  This may, indeed, be the case with telephony.  Already, there are many sites springing up to address the challenges and opportunities in combining telephony application with Linux.  Among the most useful of these sites for the truly techie is www.linuxtelephony.org

Here you will find postings and solid answers regarding a wide range of issues including:  “Is there anything that can let my linux box talk to a mac user over the internet? What is the preferred linux-to-mac software?” 

There’s also a wealth of information at this Linux telephony site: www.voxilla.org
“This site hosts open-source telecom software. It is a generally useful resource for those who need to implement telecom apps on GNU/Linux. 

In detail:

The broad goal of voxilla.org is to host a complete set of telecommunications modules for use with the GNU/Linux operating system. To that end, voxilla.org tracks, archives, documents, and develops such software. The development focus in on server-side solutions. The minimum goals set for voxilla are to have a complete archive, and to be responsive to developers who need to host software.” 

A great resource for finding Linux telephony equipment is the wel-organized and humorous www.linuxjack.com When visiting their site, sign up for one or more of their mailing lists – always informative and always cutting-edge. 

If you are exploring telephony applications for the first time and are a new-comer to considering Linux, you might enjoy getting the big picture on the Linux issue first from those inventing it.  Amazon.com offers Open Sources: Voices from the Open Source Revolution.  Here’s what their editorial review say of this book: 

“[It] is a fascinating look at the raging debate that is its namesake. Filled with writings from the central players--from Linux creator Linus Torvalds to Perl creator Larry Wall--the book convinces the reader of the overwhelming merits of freeing up the many iterations of software's source code.”