After a few days of intensive work Unity was moved to GitHub from Assembla which hosted the project for nearly 5 years.
The new source code repository address is:
This change was motivated by the fact that Assembla is moving away from providing free hosting for Open Source projects. Unity project was not closed but there were numerous signs that the plan that Unity project was using is significantly deprecated. GitHub was the natural choice, as de facto standard hosting provider for Open Source community.
Unity issues tracker was moved to our own JIRA instance. We managed to preserve a complete history, loosing only some minimal parts of tickets metadata.
Currently wiki is still in the process of being migrated.
Big thank you to Assembla for a long and actually very productive service!