The Kannel Open Source WAP and SMS gateway works as both an SMS gateway, for
implementing keyword based services via GSM text messages, and a WAP gateway,
via UDP. The SMS part is fairly mature, the WAP part is early in its
development. In this release, the GET request for WML pages and WMLScript
files via HTTP works, including compilation for WML and WMLScript to binary
forms. Only the data call bearer (UDP) is supported, not SMS.