In this article, a new content-centric collaboration platform called active content collaboration platform which supports automated content-centric collaboration on cloud system is presented. It supports event-driven automatic collaboration by specifying each active work based on active work description language and automating the execution of collaborative task flow composed of active works. It supports a modularized and extensible architecture by making its components in separate modules. Also, it provides a scalable high-performance architecture by supporting multi-level active work processing in active work execution engine, and allocating virtual machines for the computation intensive high-level action such as volume rendering through auto-scalable allocation on cloud system. For the experiment and evaluation, we shall show the results of implementing the collaborative medical application on our system where computation intensive application like a volume rendering is used for MRI analysis.