Links:

Cluster links:

beowulf.org
MOSIX Cluster Management
the openMosix Project
ClusterN Linux
TOP500 SUPERCOMPUTER SITES
HPC Grid Computing
Globus Toolkit
Linux Cluster HOWTO
LAM/MPI Parallel Computing
The Message Passing Interface (MPI) standard
MPICH - A Portable Implementation of MPI
PVM - Parallel Virtual Machine
Portable Batch System

Others:

Adam Mickiewicz University in Poznan
Faculty of Mathematics and Computer Science UAM
Computer Science Student Association
Computer Science Student Association - Linux section
Greater Poland Programming Challange
acm.edu.pl
sourceforge.net