JDep is a Java dependency analyzer with nice GUI code in MFC and some Interpreter code, Class file parser etc. and bytecode displays
This is based on Java Virtual Machine Specification 1.2. There is an in-built code for Amended strings called Springs where the length is stored in front of the string for quick comparison. There is a Memory Manager implementation based on the Buddy System algorithm. There is self-contained Zip/Unzip code out of uzip implementation All in C.