Smash

SMaSh is a program for sending messages to digital phones, pagers and other devices you can communicate with. Smash is actually a rewrite/cleanup of "SMS Server" that Björn wrote several years ago. This new version, written by Björn and Daniel, sports all the predecessors fancy features, and some more:

• Client/server architecture. One server does the SMS gruntwork, while a lightweight, portable client can be used from anywhere to submit messages.
• Dynamic plugin system that lets you add, delete or modify operator protocol plugins on the fly, without restarting the server.
• Message spooling. Buffering submitted messages for a while and then sending them all at once result in substantial cost savings for those protocols that rely on dial-up delivery.
• Open, HTTP-like protocol allowing anyone to create their own client.

Smash is released under the GNU General Public Licence, GPL, making it entirely free and open software.

http://smash.sourceforge.net/