ACTIVE is an European Union funded Integrated Project running from 2008 to 2011. ACTIVE aims to increase the productivity of knowledge workers in a pro-active, contextualised, yet easy and unobtrusive way. The aim is to convert tacit and unshared knowledge – the "hidden intelligence" of enterprises – into transferable, interoperable and actionable knowledge to support seamless collaboration and to enable problem solving. A key aspect will be support for informal procedural knowledge - the informal collaboration and problem-solving tasks that drive much knowledge work in the enterprise. ACTIVE will integrate concepts, methods and tools from the fields of: # Social Software and Web 2.0, # Semantic Technologies, # Context Mining, Context Modelling, and Context Sensitive Task Management, and # Knowledge Process Mining, Knowledge Process Modelling and Pro-Active Knowledge Process Support into highly innovative application systems. The development will be accompanied by an analysis of key economic and organizational factors and incentive mechanisms, and strongly user-centric system development and evaluation.