Event stream transformations

The formulation of transformations on one or more input event streams to generation one or more output event streams. Accordingly, the transformations may be considered to be a query on the original input event stream(s). The event query includes event stream source representations representing an input event stream available in a particular execution context. The event query also includes a transformation module identifying the transformation set to be performed on the input event streams in the execution context. Once the query is properly formed, an execution module may then cause the transformations to be executed upon the designated input event stream(s) to generate output event streams.