getting started with SMS developement

Question

i will have the following set up:

people will be sending text messages to a server, and that server will be forwarding the messages to other phone numbers

i am n

Answer 1

I used to use this website: www.aspsms.com.

It provides a lot of libraries in different languages, the prices are affordable (I think) and they offer some kind of "2 ways service".

are there already developed frameworks that are free which i can use?

Free, that would surprise me.