The parallel computation and simulation Laboratory (PacsLab) supports research that is experimental and multidisciplinary. The emphasis is on methodologies and tools for seamless, secure, scalable and fault-tolerant concurrent computing on heterogeneous networked computing platforms. Central to this effort is the notion of domain-oriented software support. Current projects include research on threads systems, network protocols, active messaging communications environments, integrated network services, parallel simulation systems and a threads-based MPI. The lab maintains a subnet of four Sun SPARC 5s, a 4-processor SPARC 20, a Silicon Graphics Indigo, and access to a 140-node Intel Paragon via an ATM. The lab was equipped with funding from the Department of computer sciences, NSF, ARO and ONR.