Learning about Java bytecode and the JVM

Question

In a recent question asked recently my simple minded answer highlighted many of my misconceptions about Java, the JVM, and how the code gets compiled and run. This has created

Answer 1

I learned by reading the ASM tutorial and mucking about with the library itself.

IMHO, ASM is better than BECL.

BCEL is already being used successfully in several projects such as compilers, optimizers, obsfuscators, code generators and analysis tools. Unfortunately there hasn't been much development going on over the past few years. Feel free to help out or you might want to have a look into the ASM project at objectweb. - http://jakarta.apache.org/bcel/