MPZ APRCL can prove the primality of numbers, written in C and GMP.
Decrypts JDownloader ejs files (works with Beta install too)
Spaced Repetition System to study Japanese
Run Java on the Lego EV3, NXT or RCX
JSP tag library for displaying charts in web pages
OWL2 to XML Schema generation library
Document Structuring schema for Natural Language Generation
Tools to generate and visualize artificial whole slide images
S-Match is a semantic matching framework.
A free high-performance alternative to TCP sockets
Translate SQL queries into relational algebra
A simple native java network library
Quick booting OS Built for live usb web browsing
Robots.txt parsing library
Services platform in cluster for Java.
Easy to use GlobalPlatform tool (and a Java library)
jchart2d is a real-time charting library written in java.