This application is not opensource sadly. It hasn't been updated in 2 years, and the lead dev. has declined sharing the code to prominent developers in the community many times. His response was always to download the OLD code that he used to work on, as he did't even create the software originally. Sadly, people are more about the fame, money or control than aiding the community and passing the torch to active people.
If you talk to a lot of people about map making, you'll find quite a few people that claim they've made their own application(s) to do the job, or have some amazing program and techniques, but will NOT share those resources. It's sad, and I think this mindset has set the community back over the years. Good luck with your endeavors and research.
This is one of the old code links I found.
Redmine
redmine.aksdb.de
hg.aksdb.de