Cell is a microprocessor architecture jointly developed by Sony Computer Entertainment, Toshiba, and IBM, an alliance known as "STI". The architectural design and first implementation were carried out at the STI Design Center in Austin, Texas over a four-year period beginning March 2001 on a budget reported by IBM as approaching US$400 million. Cell is shorthand for Cell Broadband Engine Architecture, commonly abbreviated CBEA in full or Cell BE in part. Cell combines a general-purpose Power Architecture core of modest performance with streamlined coprocessing elements which greatly accelerate multimedia and vector processing applications, as well as many other forms of dedicated computation.

The first major commercial application of Cell was in Sony's PlayStation 3 game console. Mercury Computer Systems has a dual Cell server, a dual Cell blade configuration, a rugged computer, and a PCI Express accelerator board available in different stages of production. Toshiba has announced plans to incorporate Cell in high definition television sets. Exotic features such as the XDR memory subsystem and coherent Element Interconnect Bus (EIB) interconnect appear to position Cell for future applications in the supercomputing space to exploit the Cell processor's prowess in floating point kernels. IBM has announced plans to incorporate Cell processors as add-on cards into IBM System z9 mainframes, to enable them to be used as servers for MMORPGs

The Cell architecture includes a novel memory coherence architecture for which IBM received many patents. The architecture emphasizes efficiency/watt, prioritizes bandwidth over latency, and favors peak computational throughput over simplicity of program code. For these reasons, Cell is widely regarded as a challenging environment for software development. IBM provides a comprehensive Linux-based Cell development platform to assist developers in confronting these challenges. Software adoption remains a key issue in whether Cell ultimately delivers on its performance potential. Despite those challenges, research has indicated that Cell excels at several types of scientific computation.

In November 2006, David A. Bader at Georgia Tech was selected by Sony, Toshiba, and IBM from more than a dozen universities to direct the first STI Center of Competence for the Cell Processor. This partnership is designed to build a community of programmers and broaden industry support for the Cell processor. There is a Cell Programming tutorial video available.