This Bloor Research report describes the technology and what it is good for, including providing a series of use cases. In other words: what event processing is, how it works and where you might use it. It also describes and resolves (in so far as that is possible) the issues mentioned. In addition, the report compares and contrasts the various vendors/products in the market, including: Agent Logic, AleriLabs, AptSoft, Coral8, GemStone, Leanway, Kaskad, Progress, SeeWhy, Streambase, Syndera, Tibco and the open source Esper. It also considers specialised solutions from the likes of Microsoft, SAS and Sybase as these vendors seek to move into this marketplace.