Open Source

You'll notice that most of the programs recommended in this FAQ are designated as open source. This means that the source code (the part that defines what the program does) is available for anyone to view and edit, so technically-minded people can write all sorts of handy extensions and plugins, making these programs extremely flexible and customizeable. (A look at the Firefox extension page shows just how much you can tailor a program to your needs.) For the security-conscious, vulnerabilities are patched much more quickly with open source software than with commerical software. And, best of all, these programs come with no adware or spyware and are absolutely free.

In short, open source is your friend.