Cactus Embracing New Fields

The future leaders of computational astrophysics sat in a conference room in the Beckman Institute in early October 1999 to learn about the new release of a software toolkit that provides the "connective tissue" holding together task-specific computational "thorns." The tissue is Cactus, a freely available modular, portable, and manageable environment for collaboratively developing high-performance multidimensional numerical simulations. A suite of thorns are already available, most of which reflect the astrophysics origins of the code. But Cactus developers hope to change all of that by encouraging use of the software by computational researchers outside the astrophysics community.

Cactus lets traditional single processor codes be easily extended to full blown parallel applications that can run on all supercomputers, but still be developed on a simple laptop. At the same time, it provides access to a myriad of computational tools, like advanced numerical techniques (for example, Adaptive Mesh Refinement), parallel I/O, or visualization. Cactus provides a framework for numerically solving any system of partial differential equations and could be used for applications in any of the physical sciences or engineering disciplines.

NCSA Director Larry Smarr, who introduced the Cactus training session, applauded the development team for embracing the open source movement with their code. Calling Cactus "halfway between computer science and tools," Smarr underscored the value of decentralization of software authorship to create a community toolkit. Although developed and maintained by a small core team, the fact that the code is open source means that contributions can be, and are, made from the fifty or so current users.