> i did Google and also searched CentOS web-site and CentOS 5 Release > Notes but i did not find what GCC CentOS 5 uses. i need GCC 4.x for my > C++ based project work. what GCC version CentOS 5 uses as default ? Distrowatch is a good site to find a distribution main component's versions: http://distrowatch.com/table.php?distribution=centos