Java classfile assembler/disassembler and interactive low-level editor
Java Classfile assembler/disassembler and low-level interactive editor. Allows viewing and manipulation of Java class data both manually and via scripts. Load in a class file, make changes, and then save the result.
Flasm is an assembler/disassembler for Flash actionscript bytecode.
Using flasm, script authors may learn how actionscript compiler and Flash Player virtualmachine work, and tweak the compiled bytecode in SWF files for performance.
A open source java card virtualmachine implementation. And also some part of the VM code can be used as part of kinds of tools such as javacard bytecode disassembler.