WOS stands for Web server on Stick, which is pretty much what it is. To some people this product might seem a bit unnecessary but if you are a web-developer using PHP and Apache WOS is a godsend.
WOS emulates an Apache and MySQL server on any USB-stick. The installation process is easy; CH Software has developed an online wizard called the WOS Mixer that helps you through it. When using the mixer you will be asked if you want to update your existing WOS-package or make a new one. After that a list comes up with a bunch of GPL-software, there is a lot of server stuff such as Apache 2, MySQL 5 and PHP 4 or 5. The list also contains a number of CMS-systems such as MediaWiki, Drupal, Joomla, Mambo, TYPO 3 and WordPress.
The wizard then creates a downloadable .zip file, after the download extract the zip-file and follow the on-screen instructions. If everything goes well your USB-stick will then work as a web-server with several CMS-systems installed.
It is also easy to import database copies from other sites into WOS (using PHPMyAdmin), when importing a whole site structure remember to change config settings so that the paths reflect the ones on the USB-stick.
When WOS is installed it is simply a matter of running the executable on the USB-stick. The software has a number of options, but nothing too spacey. It is possible to set the URL that is typed in the browser to reach the WOS-server. There are also some options that clear all Apache and MySQL logs when WOS is ended. WOS Portable II can also receive updates and it even has a backup feature if you want to backup the databases.
Carrying WOS Portable II around is a breeze, I have tried it for several months and it always impresses clients when it is possible to show the actual sites almost ready with server-side scripting and all. This is also a good product if you run servers or large-scale websites where you want one platform to test things on before releasing them publicly. WOS works perfectly in Firefox and Internet Explorer, it might work in other browsers as well but I have not been able to test. It also works on Windows XP/Vista and Linux.