1. A system for parallel analytical processing of data streams, the system comprising: a converter that receives input streams of data in a plurality of formats including input data streams in table, text, feed and graph formats and transforms said streams in table, text, feed and graph formats 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; a graphical user interface comprising an add-in to a spreadsheet application enabling a user to visually construct parallel analytical programs for analytical processing of streams in the standardized data stream format within the spreadsheet application using graphical building blocks, wherein a parallel analytical program comprises a linear sequence of program building blocks for performing operations on a data stream in parallel, wherein each stream of data is represented in the graphical user interface in a two-dimensional cell-based format, wherein the graphical user interface performs continuous static dependency and type checking during construction of parallel analytical programs; and a runtime computing system comprising a cluster of distributed parallel processing computing nodes connected by a network running multiple parallel analytical programs continuously on the streams in the standardized data stream format as they flow through the storage system, wherein the runtime computing system operates concurrently with the converter and storage system to perform tasks of converting multiple source data streams into the standardized data stream format, maintaining an interval of multiple data streams and running multiple parallel analytical programs on multiple data streams.