Tropo is an API that you can use in order to embellish any programming language that you regularly use with voice, SMS, IM and Twitter functionalities. That is, you will be able to use the technology that you have always used and the API provided by Tropo will let you implement real time communications into your apps
There exist two APIs that you can employ, actually.
The first is based on the cloud, and it goes by the suitable name of Tropo WebAPI. Properly speaking, this Web API is a RESTful API that talks with your actual app over HTTP, no matter where it is located. Whenever a request arrives from the user (IE a voice call, a text message or an instant message) Tropo connects with your own server and processes the commands.
On the other hand, those who are more knowledgeable will like to try the Tropo scripting API. This is the one giving any programming language the ability to make calls and send both IM and SMS messages
I feel I should not carry on for the mere reason that this is getting a bit too technical. I also think you have already gotten the gist by now, and those among you who are technically-minded will know if this is for them or not. Just one last thing, though – Tropo can be fully tried for free.
Tropo.com In Their Own Words
“Tropo is a powerful yet simple API that adds Voice, SMS, Twitter, and IM support to the programming languages you already know.”
Why Tropo.com It Might Be A Killer
Developers that are looking for ways in which to provide their apps with advanced functionalities without incurring into exorbitant costs or spending a lot of time could find this very suitable indeed.
Some Questions About Tropo.com
How knowledgeable must you be in order to maximize something like this? 
