Most mainstream operating systems today are Unix compatible. Microsoft Windows is the only mainstream operating system that is not Unix compatible, but there are free compatibility systems available for Windows to provide some degree of compatibility and interoperability with Unix.

The de facto standard of Unix compatibility for Windows is Cygwin, http://cygwin.com, which is free and installs in about 10 minutes. There are alternatives to Cygwin, but Cygwin is the easiest to use and offers by far the most features and software packages.

Another option for running Unix programs on a Windows computer is to use a virtual machine (VM). This is discussed in Chapter 40, Running Multiple Operating Systems.

Lastly, many Windows programs can be run directly under Unix, without a virtual machine running Windows, if the Unix system is running on x86-based hardware. This is accomplished using WINE, a Windows API emulator. WINE attempts to emulate the entire Windows system, as opposed to virtual machines, which emulate hardware. Emulating Windows is more ambitious, but eliminates the need to install and maintain a separate Windows operating system. Instead, the Windows applications run directly under Unix, with the WINE compatibility layer between them and the Unix system.

While it is possible to create a Unix-like environment under Windows using a system such as Cygwin, such systems have some inherent limitations in their capabilities and performance. Installing a Unix-compatible operating system directly has many benefits, especially for those developing their own code to run on the cluster.

Many professional quality Unix-based operating systems are available free of charge, and with no strings attached. These systems run a wide variety of high-quality free software, as well as many commercial applications. Hence, it is possible for researchers to develop Unix-compatible programs at very low cost that will run both on their personal workstation or laptop, and a cluster or grid.

One of the easiest Unix systems to install and manage is GhostBSD, a free, open source derivative of FreeBSD with a simple graphical installer, "Control Panel", and software manager:

A GhostBSD system running XFCE desktop.

GhostBSD is extremely easy to install and manage, as well as extremely reliable. If you want to try out Unix while encountering as few hurdles as possible, GhostBSD is probably your best bet.

Similar to GhostBSD are the Ubuntu family of Linux systems (Ubuntu, Kubuntu, Xubuntu, Edubuntu, ...). Each of these Linux distributions is built on Debian Linux, with a different desktop environment. ( Ubuntu uses Gnome, Kubuntu KDE, Xubuntu XFCE, etc.)

Another alternative for the slightly more computer-savvy is to do a stock FreeBSD installation and then install and run the sysutils/desktop-installer port. This option simply helps you easily configure FreeBSD for use as a desktop system using standard tools provided by the system and FreeBSD ports. The whole process can take as little as 15 minutes on a fast computer with a fast Internet connection. Just run desktop-installer from a terminal and answer the questions.

A FreeBSD system running Lumina desktop.

The Debian system itself has also become relatively easy to install and manage in recent years. It lacks some of the bells and whistles of Ubuntu, but may be a bit faster and more stable as a result.

A Debian system running XFCE desktop.

All of these systems have convenient methods for installing security updates and minor software upgrades.

When it comes time for a serious upgrade of the OS, don't bother with upgrade tools. Back up your important files, reformat the disk, do a fresh install of the newer version, and restore your files.

Many hours are wasted trying to fix systems that have been broken by upgrades or were broken before the upgrade. It would have been faster and easier in many cases to run a backup and do a fresh install. You will need to do fresh installs sometimes anyway, so you might as well become good at it and use it as your primary method.