Chapel is a new parallel programming language being developed by Cray Inc. as part of the DARPA-led High Productivity Computing Systems program (HPCS). Chapel is designed to improve the productivity of high-end computer users while also serving as a portable parallel programming model that can be used on commodity clusters or desktop multicore systems. Chapel strives to vastly improve the programmability of large-scale parallel computers while matching or beating the performance and portability of current programming models like MPI.


Chapel supports a multithreaded execution model via high-level abstractions for data parallelism, task parallelism, concurrency, and nested parallelism. Chapel's locale type enables users to specify and reason about the placement of data and tasks on a target architecture in order to tune for locality. Chapel supports global-view data aggregates with user-defined implementations, permitting operations on distributed data structures to be expressed in a natural manner. In contrast to many previous higher-level parallel languages, Chapel is designed around a multiresolution philosophy, permitting users to initially write very abstract code and then incrementally add more detail until they are as close to the machine as their needs require. Chapel supports code reuse and rapid prototyping via object-oriented design, type inference, and features for generic programming.


Chapel is a new language and is not mature enough to be widely adopted. Chapel compiler still considered prototype, i.e. limited use for production environment.

License: BSD open-source license

Additional Information

D. Callahan, B. L. Chamberlain, and H. P. Zima. The Cascade high productivity language. In Proceedings of the Ninth International Workshop on High-Level Parallel Programming Models and Supportive Environments, pages 52–60. IEEE Computer Society, 2004
B. Chamberlain, D. Callahan, and H. Zima. Parallel programmability and the Chapel language. In Int’l J. High Performance Comp. Apps., volume 21, pages 291–312, Thousand Oaks, CA, USA, 2007. Sage Publications, Inc
SJ Deitz, BL Chamberlain, and MB Hribar. Chapel: Cascade High-Productivity Language An Overview of the Chapel Parallel Programming Model.