Flasm disassembles your entire SWF including all the timelines and events. Looking at disassembly, you learn how the Flash compiler works, which improves your ActionScript skills. You can also do some optimizations on the disassembled code by hand or adjust the code as you wish. Flasm then applies your changes to the original SWF, replacing original actions.
It's also possible to embed Flasm actions in your ActionScript, making optimizing of large projects more comfortable.
Flasm is not a Decompiler. What you get is the human readable representation of SWF bytecodes, not ActionScript source. If you're looking for a decompiler, Flare may suit your needs. However, Flare can't alter the SWF.
Page too long? You don't have to read it all. First, make yourself familiar with usage. Then read flash virtual machine Topic to understand the concept of registers and stack. Disassemble some of your SWFs, starting with simpler ones, to see the inner workings of the Flash compiler. The rest of this page tries to address questions you may have at this point.
