The modern Java bytecode editor

An easy-to-learn/use static analysis framework for Java

Burp plugin able to find reflected XSS on page in real-time while browsing on site

TLS-Attacker is a Java-based framework for analyzing TLS libraries. It can be used to manually test TLS clients and servers or as as a software library for more advanced tools.

A natural evolution of Burp Suite's Repeater tool

Binary Instrumentation of Android Apps

Compiler from the famous Dragon Book (Compilers: Principles, Techniques, and Tools (2nd Edition)) in Java.