What version of the MacOS is pre-installed on the MacBook Pro?

All MacBook Pro models introduced prior to the "Early 2008/Penryn" systems originally shipped with a version of MacOS X 10.4 "Tiger". The currently shipping models ship with a version of MacOS X 10.5 "Leopard".

For the particular build number, please refer to "MacOS: Builds Included with Intel Macs" from the Apple Support Site.

Can the MacBook Pro run existing MacOS X applications?

A good percentage of MacOS X applications written for PowerPC-based systems can run on the MacBook Pro, and other Intel-based Macs, using the "Rosetta Universal Binary Translator", but as one would expect, these applications will run more slowly than they would if they were "native" for Intel-based processors.

The always excellent MacInTouch has prepared a list of "Universal Binary" applications that will run natively on the MacBook Pro and other Intel-based Macs. The same website also has a list of applications written for the PowerPC with readers opinions regarding their performance using "Rosetta". You may wish to consult these lists to ensure compatibility with any particular application of interest.

For more on Rosetta, please refer to "What is Rosetta? What does it support?" from the "Macintel" Q&A.

Can the MacBook Pro run MacOS 9/Classic applications?

Apple provides no support for running MacOS 9 or the "Classic Environment" on Intel-based Macs like the MacBook Pro. The MacBook Pro relies on the "Rosetta Universal Binary Translator" to run software for MacOS X for PowerPC, and this emulator cannot run "MacOS 9/Classic" applications.

If you have a mission critical application that only runs on MacOS 9, you likely would be best served by maintaining a PowerPC-based Mac. However, you also may be interested in reading "Are there any third-party programs to run MacOS 9/Classic applications on Intel Macs?" from the MacOS 9/Classic Support Q&A.

Site sponsor OHS specializes in refurbished, and often heavily upgraded, systems capable of booting in both MacOS X and MacOS 9. Site sponsor PowerMax also sells systems capable of running MacOS 9/Classic. Other resellers are available as well.

Can the MacBook Pro run Windows?

Yes. For those unfortunate ones condemned to use Windows, the Windows on Mac Q&A provides answers for just about everything you need to know about running Windows on the MacBook Pro or any other Intel-based Mac.

Can the MacBook Pro run Linux?

Yes. The MacBook Pro is capable of running a number of Intel-based distributions of Linux through Apple Boot Camp or by using "virtualization".

For more on Boot Camp and Virtualization, please refer to the Windows on Mac Q&A.