Stylish

All people want to leave their fingerprints behind and have a sense of ownership. When it comes to personalizing the computer desktop, users usually turn to the newest and most popular findings in wallpapers, screensavers and widgets. However, there are other options as well, such as web browser plug-ins.
Stylish is a useful add-on supported by Firefox, Thunderbird and SeaMonkey. It provides a simple and quick method to create and manage user styles. Thus, you can design a nice UI without putting too much effort into it.
Once the plug-in is installed, you can view the Stylish bar on the bottom part of the web browser.
So, you can access 'Add-ons Manager' and create a new style (for the current URL or blank style) by specifying a name, tags and objects to be inserted (HTML or XUL namespace as default, Chrome folder path, data URI). It is also possible to use a search function and preview results.
The simplistic tool obviously requires some web design experience but its features are not too advanced. Luckily, Stylish does not require you to restart the web browser in order to apply changes. The app puts little strain on the computer's CPU and system memory; it has not intervened with the good functionality of Firefox during our tests. Chrome users will be happy to know they may also access Stylish's features via Stylish for Chrome.