The preferred method for installing and using the Perl module is to install it from CPAN.
cpanm Geo::DNA
However, you can also get the source directly from the github repository:
https://github.com/quile/geodna-perl
The Javascript github repository is here:
https://github.com/quile/geodna-js
The Ruby version is not yet packaged up as a gem, but will be soon. For now it's available from github:
https://github.com/quile/geodna-ruby
The Python implementation of this system is called "geoprint" and is part of the "xodb" package found here:
https://bitbucket.org/pelletier_michel/xodb
Note that although it produces and consumes the same codes, the naming is a bit different and the API does not correspond exactly.
Once installed, you can use perldoc Geo::DNA for documentation, or find it at the github repo, listed above.
The javascript documentation can be found at the github repo, listed above.
The file xodb/tools/geoprint.py in the source of the repo listed above has decent documentation.