The OSCAR working group has released a new version of the Open Source Cluster Application Resources (OSCAR) toolkit, OSCAR 3.0. OSCAR is a software package that supports high-performance computing by reducing the work of cluster configuration, installation, operation, and management. Enhancements in the 3.0 release include the ability to install and uninstall OSCAR packages after a cluster has been installed and a more expressive packaging API. OSCAR 3.0 also includes the new LAM/MPI 7.0 communications library, the C3 toolset v4.x, SIS updates, including multicast install updates, 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 the OSCAR Package Downloader (OPD) and then installed as part of normal OSCAR installation. OSCAR 3.0 has been fully tested for use with IA32 processors, under Red Hat Linux 8.0, 9 and Mandrake Linux 9.0. Those seeking Itanium processor family support should continue to use OSCAR version 2.2.1. Information about the OSCAR project, including links to current and all previous versions, can be found at http://oscar.openclustergroup.org. The OSCAR working group is a consortium of industry, academic and research participants. Primary contributors include Bald Guy Software, Dell, IBM, Intel, Indiana University, the National Center for Supercomputing Applications, Oak Ridge National Laboratory (ORNL), and Universite de Sherbrooke. OSCAR is the product of the OSCAR working group of the Open Cluster Group (OCG). OCG is dedicated to making cluster computing practical. The OCG and its subgroups are open to all.