SMSD supports text messages in GSM, ISO8859-15 and UCS2 (Unicode) alphabet. It can supports also binary messages like ringtones and operator logos.
SMSD can be used with up to 32 modems and it can run on a set of networked computers for redundancy.
SMSD runs on Windows, Linux, Solaris, MacOS, FreeBSD and possibly on all other Unix-style operating systems.
That's it.
If you have further questions, please take a look at the project homepage or feel free to ask me via email.