PCSX2 is a PlayStation2 emulator that supports a lot of games on that console.
In order to use this emulator it is necessary to download some of the BIOS of Play Station, and then configure the different controls, audio and other elements. It allows playing both from the CD or DVD reader as from the disc as it reads the .ISO images that have been created from the games.
On the official page you can consult the installation guide in Spanish. Although the new version includes a wizard that facilitates the configuration, it is recommended to read the instructions and follow the necessary steps for the installation.
During the installation you can select the plugins that you want to use or leave the ones that come by default. You should also choose the BIOS image from a list.
PCSX2 1.0 is the new version 2012. It works for Windows, Linux and Mac OS X, being free for all these platforms.