1. A system for parallel processing of data streams, the system comprising: a converter that receives input streams of data in a plurality of formats and transforms said streams into a standardized data stream format comprising rows and columns in which values in a given column are of a homogeneous type; a storage system that continuously maintains a finite interval of each stream in the standardized data stream format subject to specified space limits for the stream; an interface enabling a user to construct parallel stream programs for processing streams in the standardized data stream format, wherein a parallel stream program comprises a linear sequence of program building blocks for performing operations on a data stream; and a runtime computing system running multiple parallel stream programs continuously on the streams in the standardized data stream format as they flow through the storage system.