Ubuntu - free Operating System for your PCs and Macs
I have been using Ubuntu linux for quite sometimes now. I think it is a great alternative to commercial Operating Systems such as Vista and OSX. So far, I have tried Ubuntu as well as Xubuntu. Xubuntu is a faster and lighter version of Ubuntu that can work well with older and less powerful PCs.

In the past, Linux was difficult to use. With the advent of the newer versions of Ubuntu, this is no longer true.
If you are looking for a free yet highly usable OS for your computer, Ubuntu is your best bet.
In my case, it detected all my hardwares which includes internet connection, printer, sound card, etc.
In addition to that, there are many free alternative to commercial applications that are available on Ubuntu. The following are some of them:
1. Kompozer for Web editing.
2. GIMP for Image editing
3. Blender 3D for 3D modelling and animation
4. Open Office for Office applications
5. Firefox for Web surfing
The best thing is , all these free yet powerful programs can be very easily installed using Synaptic on Ubuntu which will search the web for these application and install them as long as your internet connection is connected. This is so easy and convenient.
Ubuntu can maintain some kind of compatibility with Windows through the installation of the Wine application. Wine is a Microsoft Windows emulator that allows Windows programs to be installed and run within the Ubuntu environment. I have manage to install and run some of the Windows-based program using Wine. However, I must honestly say that not all Windows-based program will work with Wine.
In conclusion, Ubuntu can be a serious replacement for commercial Operating System.