Feel free to add to this list!
- Ironspeed - database-driven web development using ASPX in an MVC architecture.
- CodeCharge - web development in ASP.NET (C#), ASP, PHP, Java Servlets, JSP, ColdFusion and Perl.
- Ruby on Rails - "... an open-source web framework that's optimized for programmer happiness and sustainable productivity." Emphasis on convention over configuration.
- uniPaaS - RAD environment to produce Rich Internet Applications. "Do it Once. Do it Right. Total Mobility Experience."
- EBase Xi - "Ebase Xi combines browser and mobile app development, data integration and enterprise workflow to deliver the world's best rapid application development platform"