Developer Studio is a one-stop solution for almost all the development tools you will ever need for creating middleware applications based the award-winning WSO2 Carbon platform. It provides a complete Eclipse-based SOA development environment and immensely simplifies creation of artifacts with graphical editors and management of the links and dependencies between these services. You can easily test, debug, and deploy your artifacts as Carbon Application aRchives (CAR) onto your WSO2 Carbon-based servers or onto a WSO2 Stratos-based cloud.
We have WSO2 Developer Studio 3.5.0 Beta 2 ready to be downloaded. The major improvement of DevS 3.5 is ESB graphical editor , follow the link here to get abstract view of improvement.
DevS distrubution available here for linux, windows and mac platforms.