Hello fellow VM developers! As mentioned on #classpath I released javver, a tool for generating random Java bytecode that is useful for testing VMs. You can get more details on http://stud4.tuwien.ac.at/~e9825234/javver/ Currently javver uses only instructions for primitive arithmetic and stack manipulation, but it already proved very useful in testing CACAO. The generated bytecode tends to be very different from what Java compilers emit, so it triggers bugs that are otherwise hard to detect. The biggest problem right now is locating a detected bug in the crazy bunch of bytecode that javver emits, but I have ideas for automating that. Cheers -Edwin