OST
Open Source Telephony, or OST as it is referred most often in most of the publications, is a set of
products, solutions, and toolkits avaliable freely (mostly) on the internet, that in one way or another
are capable of providing services or support services involving telephony over the variety of IP based
protocols.
That's a vague description of a fairly new, but very vivid movement on the Voice Over IP front,
where the idea of allowing anyone with a server and the right software, for which the source code is
freely available, to run their own telephony infrastructure, with services and features limited only
by their imagination.
Some of the best known, and most popular products in this area are presented in here.