As it says at Wine HQ:
Wine is a translation layer (a program loader) capable of running Windows applications on Linux and other POSIX compatible operating systems. Windows programs running in Wine act as native programs would, running without the performance or memory usage penalties of an emulator, with a similar look and feel to other applications on your desktop.
The Wine project started in 1993 as a way to support running Windows 3.1 programs on Linux. Bob Amstadt was the original coordinator, but turned it over fairly early on to Alexandre Julliard, who has run it ever since. Over the years, ports for other Unixes have been added, along with support for Win32 as Win32 applications became popular.
I run all Linux all the time on all my boxes at home. But, at the high school where I teach computer science, it's MS-Windows XP. In fact, our teacher attendance keeping and electronic gradebooks are MS-Windows programs run from a Netware server.
My teacher computer has been Linux/WinXP dual-boot now for 3 years. I would boot into WinXP when taking attendance, looking up student data, or entering assignments into the gradebook.
However, I prefer "living in Linux". Our student school admin/data program is called "ClassXP.exe". The gradebook program is called "Integrade Pro" and the file is "IGPro32.exe".
OK, I worked out all the stuff about connecting to our Netware servers from Linux using "ncpfs" (Netware Core Protocol File System). Since my school district is using reasonably recent versions of the Netware server software, I'm able to make an IP connection to the server from a Linux client rather than using the native Netware IPX protocol. The IP connection seems to be faster and more reliable than the IPX connection.
But, last year, Wine would only "sorta" work with the ClassXP software. Sub-windows weren't properly updated, and it crashed often. Worse, the Integrade gradebook program wouldn't run at all under Wine.
This school year is a different story. Yes, the IP connection is better versus IPX. But, the best news is that both ClassXP and Integrade work perfectly using Wine under Linux.
This came about when I installed Wine version 0.9.46 this last September (latest version is 0.9.47, but my Distro hasn't packaged this version yet, and I don't want to compile and install from source).
Now, my teacher computer can "live in Linux" all the time!
Do I wish our school district was using FOSS student administration software such as "Open Admin" by Les Richardson? Yes, I do--and I think it will happen some day. But until it does, I'm really delighted to be able to run these two proprietary MS-Windows programs using Wine under Linux.
So, I'm at home earlier this week, playing around with one of my home machines. On a whim, I decide to install the MS-Windows version of Mozilla-Firefox to see if it will run under Linux Wine. Short answer--it installs and runs as fast as the Linux version--I'm amazed. So, I decide to install the windows version of the Adobe flashplayer plugin to see if I can play flash videos from the Windows Firefox version under Linux Wine. Much to my surprise, this works, and works very well.
Wine is at version 0.9.47. As it nears version 1.0, it's becoming clear that the goals of the project are being met. Kudos to the Wine developers!