This is the git source archive for the DPR.

Each set is in its own subfolder, and each set has a build.sh script that will create the xpi for use with Firefox.  Better than this, though, is to simply create a link to the set directory in your Firefox profile's "extensions" directory.  To do this, create a file for the set, named:

<directory>@noah.yuttadhammo

with the location of the directory as the first and only line of the file, i.e.:

/path/to/directory

For example, create a file in your profile's "extensions" directory called:

digitalpalireader@noah.yuttadhammo

and put the following in it:

/path/to/digitalpalireader

(replacing "/path/to" with the actual path of the digitalpalireader directory on your machine).

Do this for each extension and then start Firefox.