Too bad you didn't mention the option of maintaining separate code-bases. Very often when you get to the download page of an app they offer an old pre-tiger version and a tiger version. While it is obvious that the pre-tiger version would lack features, atleast there is something available.
Especially when updating an existing app to use a newer version of OS X, why not offer a friendly licensing scheme that allows a buyer to use the old version for now and let him get the new version for free when he had the chance to upgrade.
The different versions will grow apart in features rapidly, and perhaps you'll stick to bugfixing the old version, but atleast you don't leave a user out in the cold. Especilly since before updating your codebase to the latest and greatest you already had a tested release available to the old world.
by Jeroen Leenarts — Jan 03
Especially when updating an existing app to use a newer version of OS X, why not offer a friendly licensing scheme that allows a buyer to use the old version for now and let him get the new version for free when he had the chance to upgrade.
The different versions will grow apart in features rapidly, and perhaps you'll stick to bugfixing the old version, but atleast you don't leave a user out in the cold. Especilly since before updating your codebase to the latest and greatest you already had a tested release available to the old world.