Difference between RoboHelp and FrameMaker

Hello All,

Can someone provide technical and functional difference between RoboHelp and Framemaker tool.

Client want to move out from RoboHelp and need to implement the Content Management System like Documentum for more re usability and better end user experience.

Any one have comparison of things between these 2 tools.

Things can be achieved by RoboHelp cannot be achieved by FrameMaker?

Thanks in advance!