OAK RIDGE, Tenn. -- The OSCAR working group has released a new version of the Open Source Cluster Application Resources (OSCAR) toolkit, OSCAR 2.3.1. OSCAR is a software package that supports the use of high-performance computing by reducing the work of cluster configuration, installation, operation, and management. Enhancements to previous versions of OSCAR in OSCAR 2.3.1 include a faster, multicast-based version of the OSCAR installer; a more scalable version of OSCAR's remote command execution toolkit; a more expressive packaging API, which allows package authors to more easily convey package requirements; and a redesigned and improved, Qt-toolkit-based, graphical user interface for the OSCAR Package Downloader (OPD) wizard. This improved wizard enables a user to download additional packages from on-line repositories prior to the cluster install. OSCAR 2.3.1 also includes the new LAM/MPI 7.0 communications library, and supports the use of several previously unsupported software packages, including Myrinet, PVFS, and Clumon. These new packages can be downloaded at the start of an installation via OPD and then installed as part of normal OSCAR installation. OSCAR 2.3.1, has been fully tested for use with IA32 processors, under Red Hat 8.0, 9.0 and Mandrake 9.0. Those seeking IA64 support should use version 2.2.1 of OSCAR for now. OSCAR 2.3.1, OSCAR 2.2.1, and additional information about the OSCAR project are available from the OSCAR project page: http://sourceforge.net/projects/oscar/