Open ERP running on Centos 5

yum install libxml2
yum install postgresql
yum install postgresql-devel
yum install python-devel  // python 2.4.3
yum install libxslt-python
mkdir -p /opt/tinyerp/src/
cd tinyerp/src/
yum install mx
yum install vim-enhanced
yum install python-psycopg
yum install python-reportlab
yum install postgresql-server
yum install python-imaging
/etc/init.d/postgresql start
chkconfig postgresql on
python -c 'import sys ; print sys.path'   
wget http://heanet.dl.sourceforge.net/sourceforge/pyparsing/pyparsing-1.4.7.tar.gz
gunzip pyparsing-1.4.7.tar.gz
tar -xvf pyparsing-1.4.7.tar
cd pyparsing-1.4.7
python setup.py install
cd ..
wget http://kent.dl.sourceforge.net/sourceforge/pytz/pytz-2006p.tar.gz
gunzip pytz-2006p.tar.gz
tar -xvf pytz-2006p.tar
cd pytz-2006p
python setup.py install
cd ..
tar -xvvf tinyerp-server-4.2.2.tar
cd tinyerp-server-4.2.2
python setup.py install 

More Detail: http://openerp.com/forum/topic4024.html