Translate uses Git as its Version Control System. If you are new to Git and coming from Subversion, you may need to check out this Git - SVN Crash Course
The Translate Git repositories are hosted at GitHub. You can directly clone the repositories for the projects you are interested on hacking, but if you already are a GitHub user, you can directly fork the repositories from the GitHub web interface.
https://github.com/translate/translate
Clone command:
git clone https://github.com/translate/translate.git
https://github.com/translate/pootle
Clone command:
git clone https://github.com/translate/pootle.git
https://github.com/translate/virtaal
Clone command:
git clone https://github.com/translate/virtaal.git
https://github.com/translate/amagama
Clone command:
git clone https://github.com/translate/amagama.git
https://github.com/translate/corpuscatcher
Clone command:
git clone https://github.com/translate/corpuscatcher.git
https://github.com/translate/mtscripts
Clone command:
git clone https://github.com/translate/mtscripts.git