System Animator's Linux support is now under beta testing. I don't have a dedicated Linux machine myself, and can only test it on a VM (Virtual Machine) environment (Ubuntu running under VMware to be exact), which is inadequate considering that there are so many Linux distros out there. If you want to try System Animator on your Linux desktop, please follow the procedures below. The process will be more complicated than doing so on Windows, but since you are a Linux user, I expect that you should have some certain degree of computer knowledge, and thus this should still be easy enough for you.
Attack defines how long it takes to reach maximum compression once a signal exceeds the threshold. The Attack knob’s values are in milliseconds. Release sets how long it takes for the compressor to return to normal operation after the signal falls below the threshold. The Release knob’s values are in seconds. When Release is set to A (Auto), the release time will adjust automatically based on the incoming audio. The Glue Compressor’s Auto Release actually uses two times - a slow one as a base compression value, and a fast one to react to transients in the signal. Auto Release may be too slow to react to sudden changes in level, but generally is a useful way to tame a wide range of material in a gentle way.