Geotools - The Open Source Java GIS Toolkit
Tabifier is an IDEA plugin that respaces or tabs Java source code so that certain syntactic items are vertically aligned. Tabifier provides extensive control over alignment.
VisualLangLab is a completely visual, simple, and easy to learn IDE for developing parsers without code or script of any kind. A grammar is represented as a tree with distinct icons for various elements, and is edited by using the mouse to invoke menu-bar and context-menu operations.
Maven CSS Validator Plugin