See the Colemak Mod-DH Project Home Page for information on this project.
The fastest way to try out Mod-DH on Windows is to use the AutoHotKey scripts. See the 
autohotkey folder for downloads.
There are also files for Microsoft Keyboard Layout Creator (KLC). See the KLC folder for more information and downloads.
Mod-DH is now supported by DreymaR's Big Bag of Keyboard Tricks.
This is the recommended way to install Mod-DH in Linux. To enable it, edit the symbols/colemak file as mentioned in this Colemak forum discussion. The source files are in DreymaR's BigBagKbdTrixXKB repository.
There are currently a selection of files for xmodmap, there are available in the xmodmap folder download area. You may need to customize these for your own language/region. Keymap files for the console are also provided in the console folder.
The files can also be generated and installed by running make install in generate-linux-keymaps as root. Since the location of console keymap files varies depending on the distro, you may need to specify a different directory than the default /usr/share/keymaps (which is correct for Debian-based distros): # make KEYMAP_PREFIX=/usr/share/kbd/keymaps install.
An Android application package (APK), with source files, is available, allowing you to type Mod-DH on a physical keyboard connected to your Android device. See the android section for detailed instructions.