The Debian package was added in 3.7.19, which explains why you haven’t seen it 
Also, @uckelman has not (yet) integrated the availability in to the web-pages except in the release announcements.
The Debian package is not (yet) part of the regular Debian distribution, and you cannot get it through the regular channels you get Debian packages from. Instead, you will have to download the package and install it as explained here. Still, as simple, or simpler, than otherwise.
The main benefits of the Debian package for Debian based systems are
- Automatic dependency installation. The package pulls in all needed dependencies automatically.
- Use external third-party packages where ever possible. That means you do not have duplicates of various
.jarfiles floating around. - Full integration into the Debian system and desktop:
- File associations - Vassal files are associated with the Vassal application, which means you can open a
.vmodfile, for example, simply by double-clicking it. - Registered application. The Vassal application is registered with the desktop, which means you can launch from the regular application menus and so on.
- Documentation integration. The Vassal documentation is registered with the system so that it is available through regular documentation channels - for example
man vassal - Better launcher script. This script allows you to run
without having to prefix the module with the full path to the current directory.$ vassal -l MyModule.vmod
- File associations - Vassal files are associated with the Vassal application, which means you can open a
Yours,
Christian