Cougaar is a Java

Java (programming language)

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

-based architecture for the construction of large-scale distributed multi-agent systems. Cougaar is the product of multi-year DARPA research projects ALP and Ultra*Log.

Cougaar is open source and includes not only the core runtime framework, but also a variety of demonstration, visualization, and management components to simplify the development of complex, distributed applications.

Cougaar is an abbreviation, of sorts, for "Cognitive Agent Architecture".