Interesting project. Seems like a modern version of Kannel [1], a battle tested SMS gateway that supports a very simple HTTP interface for applications and both SMPP and EMI ECP protocols for the backend.
For an alternative Java SMPP implementation, see CloudHopper [2] (Twitter use it for its SMS infrastructure)
For an alternative Java SMPP implementation, see CloudHopper [2] (Twitter use it for its SMS infrastructure)
[1] http://www.kannel.org/
[2] https://github.com/fizzed/cloudhopper-smpp