Without knowing your level technical expertise, I can tell you that Linux is an operating system offered by different vendors.  In some cases, it is far superior to Windows and Mac.  In other cases, Mac or Windows outshines Linux. The trick, of course, is knowing which operating system to pick for the platform and purpose you have in mind.

There are a lot of myths and flat out lies about Linux in the trade media.  My personal favorite is the usability of Linux on the desktop.  There are three systems that my family uses.  One, a game machine, runs Windows XP.  The other common PC runs Linux.  I never gave instructions on how to use the Linux system compared to the Windows system.  My wife, mother-in-law, and children had no problems adjusting to Linux.

For me, the Linux on the desktop debate ended when my mother-in-law had me build a custom PC for her.  She insisted on Linux. She had a choice and a preference I was happy to oblige.

Some advantages of Linux over Windows:

• Requires less resources.
• Install it on as many systems as you like, legally, without paying for licensing.
• You can purchase vendor support at your discretion.
• A large number of on-line resources to find answers to questions.
• Less risk of virus problems. 

Linux is not right for every desktop or server.  It is, however, an option you should consider when building your organization's infrastructure.  Before getting rid of old hardware, ask yourself what unfulfilled needs you have for your organization.  Chances are, there is a Linux based, open source solution available to fill that need.