OpenXava - OpenXava is a Web Java Framework for Rapid Development of Enterprise Applications.
Vaadin Framework - Vaadin is a web application framework for Rich Internet Applications (RIA).
Grails - An Open Source, full stack, web application framework for the JVM
ProcessMaker Low Code BPM - ProcessMaker is a top-notch Low Code BPM platform used by dozens of businesses worldwide to design and deploy complex processes.
Open As App - Automatically create a business app from a spreadsheet, no coding.
Apache Sling - Apache Sling is a REST based web framework,