You don't need to fork over big bucks – or even any bucks – to keep your online activities and identity secret. The open source community has dozens of privacy-related projects in development, and some of them have already proven themselves to be among the best privacy protection tools available.

These tools are targeted at three broad groups of people. First are products aimed at the general public. Everyone with a computer needs applications like firewalls, anti-spyware, intrusion prevention, and password management. But there are also email encryption, anonymous file sharing, anonymous surfing, and other apps for those with more pressing privacy needs.

Sure, these tools can be used for nefarious purposes, but they are also used by journalists reporting from hostile environments, citizens of countries who don't respect free speech rights, military and intelligence personnel, whistleblowers, and others who worry that "Big Brother" might be watching.


Finally, open source developers have created a number of tools aimed at their fellow coders who need help adding encryption to their applications.

We've included projects aimed at all three groups in our list of 40 open source tools for protecting your privacy. So whether you're Joe Schmo or James Bond, a geek or just paranoid, you're sure to find at least a couple of apps on our list that can help you keep your personal data secret.

Anonymous Browsing

1. TorK

TorK is a frontend that allows you to access the anonymous Tor network from the KDE desktop. It gives you one-click access to anonymous surfing, e-mail, and chat. Operating System: Linux, Unix.

Anonymous Email

2. Mixminion

A type III anonymous remailer, Mixminion offers both client and server code for sending and receiving email that is difficult to trace. Note that this is still a work in progress aimed primarily at developers or the technically knowledgeable. Operating System: Windows, Unix, OS X.

3. Zmail

With Zmail, all you need to know is your SMTP server address, and you can send email "from anyone to anyone." It's great for sending anonymous messages or sending a quick message when you don't want to wait for your regular mail application to load. Operating System: OS Independent.

4. Mixmaster

The most popular implementation of the type II remailer protocol, Mixmaster makes it easy to send email anonymously or under an alias. The site offers both client and server versions. Operating System: Windows, Linux, Unix, OS X, BSD.

Anti-Spyware

5. Nixory

Nixory protects against malicious cookies and other data mining tools when you are using Firefox. It's fast and works alongside other anti-spyware and anti-virus programs. Operating System: OS Independent.

6. Remote BHO Scanner

One of the tricks spyware employs is to disguise itself as a Browser Helping Object (BHO), essentially integrating itself into Internet Explorer or other browsers. This tool finds BHOs and helps you determine if they are spyware so that you can remove them manually. Operating System: Windows.

7. SpyMonitor

This app monitors your memory usage to detect spyware while it's running. Note that this is an older project and only works with Windows XP. Operating System: Windows.

Backup

8. Areca Backup

Areca not only makes it easy to backup your system, it also compresses and encrypts your files using Triple DES and AES encryption algorithms. You can store your files on any medium, and it includes a number of advanced features such as delta backup, as of date recovery, and more. Operating System: OS Independent.

Data Destruction

9. Darik's Boot And Nuke

Before you donate that old PC, you really need to make sure you've completely destroyed all the passwords, account numbers, and other personally identifiable information it contains. DBAN does just that: just slip in a disk and it will completely erase the entire drive. Operating System: OS Independent.

10. Eraser

If you need to erase just one or two files, Eraser does the trick. It overwrites data multiple times so that it cannot be recovered with most forensic tools. Operating System: Windows.

Compression

11. PeaZip

PeaZip not only compresses files so they take up less space, it also encrypts files to secure them for transit or archival. It can create files in 10 of the most popular archive formats, and it can read files in 79 different formats. Operating System: Windows.

12. KGB Archiver

This tool combines an incredibly high compression rate with strong AES-256 encryption. On the down side, in order to use it, you'll need a fairly robust system: 1.5GHz processor and 256MB RAM is the bare minimum. Operating System: Windows, Linux, Unix, OS X, BSD.