Grails - An Open Source, full stack, web application framework for the JVM
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Vaadin Framework - Vaadin is a web application framework for Rich Internet Applications (RIA).
Retool - Build custom internal tools in minutes.
Spring Framework - The Spring Framework provides a comprehensive programming and configuration model for modern Java-based enterprise applications - on any kind of deployment platform.
Airtable Universe - Real workflows from real people