There three areas where Ubuntu and Ubuntu derivative distributions can collaborate: bug handling, code sharing, and code customizations.

1 Bug handling. Make Ubuntu's bug process compatible with derivative distribution's bug processes to ease the flow of information back and forth. This includes issue triage and automatic crash reporting systems.

2 Code sharing. Insure that Ubuntu and Ubuntu derivative distributions are able to easily share the same code base. Combine resources so that the Ubuntu and it's derivative communities' can develop and push good patches upstream.

3 Code Customizing. Insure that it is easy and efficient for Ubutu derivative distributions to customize Ubuntu code to meet their user's and customers needs.

More information can be found on our Wiki https://wiki.ubuntu.com/DerivativeTeam
Mission

Make it easy and efficient to create and maintain a Linux distribution that is based on Ubuntu