Developer website: Konstantin Anoshkin
Classic Spy installs a status bar icon, by a single glance at which you can tell whether the Classic Environment is running or not. It is a suite of two extremely lightweight applications. They consume little to no resources, so you won't notice they are there. Source code included.
Version 2.1.2 makes mess with wrong files included in 2.1.1 package fixed.
Mac OS X 10.2 or later