AzStudio - Accelerate application development in Microsoft Azure PaaS
OpenXava - OpenXava is a Web Java Framework for Rapid Development of Enterprise Applications.
Simplifier - Low-code platform to build business applications with ease
Apache Sling - Apache Sling is a REST based web framework,
Kohezion - Online database application builder
Vaadin Framework - Vaadin is a web application framework for Rich Internet Applications (RIA).