Just a suggestion for the mac version dev
If it's because you don't have a 10.6 sdk lying around, I'd be happy to help. I still have one lying around as I use it for my xboard work, where i don't use xcode. Personally I already use macports so I can't install homebrew lest it interfere with my setup. But with macports, it's easy to set all ports to build for 10.6 by adding to the /opt/local/etc/macports/macports.conf file
# MACOSX_DEPLOYMENT_TARGET - osx version to be compatible with earlier OSX version.
macosx_deployment_target 10.6
MACOSX_DEPLOYMENT_TARGET 10.6
SDKROOT /Developer/SDKs/MacOSX10.6.sdk
I have no idea how to configure this in homebrew.
then compile with the -mmacosx-version-min=10.6 -isysroot /Developer/SDKs/MacOSX10.6.sdk flags
Then you would also want to make sure the minimum version is 10.6 in the app's plist file as mentioned above.