A few folks have been inquiring about making AE compatible with Snow Leopard. The main build of AE is not compatible as a few UI elements and some code I use requires OS X 10.7 or above.
For those of you stuck on Snow Leopard without an alternative I've created a special branch of AE just for you. It's largely untested so YMMV. Furthermore, you must be running the 64 bit version of 10.6. I don't have a 10.6 machine of my own to test on, but anecdotally it works.
The Snow Leopard version has the auto-update mechanism disabled, and a few UI niceties are missing. Otherwise it's the same code as the normal version 1.3.2 build.
Updates to this build will only be done on a per request basis and I really wouldn't be able to justify adding features just to it.
Please refer to the Troubleshooting pages if you encounter any issues.
Updated 7/16/2015 to build 99006