Wikipedia
PCSX-Reloaded
PCSX is a free console emulator which allows software designed to be used with the PlayStation to be used with personal computers. Over the years, development changed hands several times with PCSX-Reloaded now being the main version.
PCSX has a high compatibility rate and is currently available for a number of different operating systems including Microsoft Windows, OS X, and various Linux distributions. Released under the GNU General Public License, PCSX is free software.