Religious arguments over alternative technologies can be fun...for a few days. Then they become wasteful. Instead of taking sides, we decided that it is important to encompass the largest possible community of developers.
The Mobicents team now offers implementations of both JSLEE and SIP Servlets. Jean Deruelle, Ranga M, Vladimir Ralev, Bartosz Baranowski and other members of the core Mobicents team built the SIP Servlets (JSR 289) implementation from scratch in less than 3 months. As can be expected it shares many of the underlying components with the existing JSLEE SIP Resource Adaptor, most notably the JSIP open source stack from NIST.
Web developers who are still shy to open the doors of the VoIP realm will find it easiest to prototype using SIP Servlets. As their needs grow with the sophistication of their converged applications, they will reach to JSLEE, which has an advanced programming model optimized for solving communications problems and a rich palette or Resource Adaptors covering a variety of telco protocols.
What is next? As we're acquiring experience with Java EE, JSLEE and SIP Servlets, we are thinking about a unified programming model. It should be intuitive to add voice and video features to an application based on EJB3 and Web Beans. Some early work shows that this is possible and we are confident it won't take long before the open source community rallies around a unified model. Join the discussions.