What Operating System do you use? Mac OS X, Windows, GNU/Linux, or UNIX BSD?

Linux.

Also, UNIX and BSD are different things.

Mac OS X is Unix :-)

Linux and BSD are unix-like but are not actually unix...

anyways, I use currently Mac OS X 10.5, 10.6 and 10.7 (pre-release), as well as Windows 7 (occasionally), Linux Mint 10, and have been playing with Ubuntu Linux 11.04.

I have Windows XP and Windows 7 machines, and two Linux (Ubuntu 14.04 distro) systems. My wife and I have an unbreakable rule to NEVER own any Apple product!

I have 1 OS X Computer, 1 Windows only computer, and one computer with Windows and Ubuntu Linux.

Currently Multi booting

2 partitions of Linux Mint 9 LTS (based on Ubuntu 10.04 LTS)

http://www.linuxmint.com/rel_isadora.php

1 partition of Linux Mint 10 (based on Ubuntu 10.10)

http://linuxmint.com/rel_julia.php

All are running Kernel 2.6.38

HowTo upgrade to Kernel 2.6.38 on Ubuntu 10.04 LTS/Linux Mint 9 LTS

https://sites.google.com/site/lightrush/random-1/h...

Installations broken down

Linux Mint 9 LTS with switchable Compiz 0.8.6 sourced from third party PPA and Compiz 0.9.2.1 compiled from source

http://www.webupd8.org/2010/06/upgrade-to-compiz-0...

http://releases.compiz.org/0.9.2.1/

Linux Mint 9 LTS with Compiz 0.9.2.1 sourced from Ubuntu Natty (Alpha 2)

Linux Mint 10 with Compiz 0.9.2.1 sourced from Ubuntu Natty (Alpha 2)

All installations are using the open source libgl1-mesa-dri-experimental driver instead of proprietary nVidia drivers (libgl1-mesa-dri-experimental driver is sourced from the xorg-edgers PPA)

https://launchpad.net/~xorg-edgers/+archive/ppa

Other operating systems

Windows 7 Ultimate SP1

Windows XP Professional SP3

LUg.