My client and I appear to have successfully protected a standalone Max application I built, using PC software from Oreans:
The key here is the "XBundler" plug-in, which allows you to "wrap" additional files into the application bundle: media, text, whatever you want. In this case, the all-important factor was the .mxf file, which is vulnerable to reverse-engineering. There is an option to bundle the file into the finished application, have it encrypted, and never be written to disk during runtime. Once the app was protected, we threw away the .mxf and everything worked just fine...the software makes a .bak file that has the .mxf encrypted inside. You then run the .exe (Max standalone app) as usual and it knows how to open it.
This was NOT straightforward, as many protection software apps don't allow this kind of bundling, they generally only protect .exe, .dll, etc., and not text files. Also it took awhile to get the settings just right, but there are a ton of options, so we needed to read the documentation carefully.
The Max standalone runs in Trial Mode until a hardware-dependent License key has been entered. This can be done with a generated .dat file or a Windows Registry Key entry.
The cost was about 450 Euros for the Single Developer License. You can allow software updates for your application as needed.
I don't know about similar software solutions for Mac, so if anyone has tips on this, I'd be very interested to hear about them.
Hope this is helpful to some!