On the upside, replacing commercial security products with open source versions gives you greater flexibility and affordability. If you long for complete control, this route is for you.

However, the downside is that you'll have to do some work to locate the right open source versions with the desired functionality, and to master the underlying technology.

To help you with that work, our colleagues at Datamation have compiled this handy dandy list of "50 Open Source Tools To Replace Popular Security Software." Among those making the cut are the following: 

1. ASSP Replaces Barracuda Spam and Virus Firewall

ASSP (short for "Anti-Spam SMTP Proxy") works with existing Exchange, Lotus Notes, or other SMTP servers to stop the delivery of spam. Note that this a product for organizations, not home users, so you will need to be fairly knowledgeable to use it. Unlike the commercial Barracuda product, it's software, not a physical appliance, and it only stops spam, not viruses. Operating System: OS Independent.

10. Web of Trust (WOT) Replaces McAfee SiteAdvisor Plus

Very similar to the SiteAdvisor, this add-on for Firefox, Internet Explorer, or Chrome rates sites on their trustworthiness. When you use one of the major search engines, WOT will show you a red, green, or yellow circle, so you know whether or not the site is safe to visit. Operating System: Windows, Linux, OS X.

16. AxCrypt Replaces McAfee Anti-Theft, CryptoForge

The self-proclaimed "leading open source file encryption software for Windows," AxCrypt makes it easy to protect files and folders in Windows. From Window Explorer, you just right-click to encrypt, and double-click to decrypt data. Operating System: Windows.

And

45. John the Ripper Replaces Access Data Password Recovery Toolkit, Passware

Especially good at finding weak passwords, John the Ripper searches lists of common passwords looking for a match. It's not as good with strong passwords as the commercial apps or Ophcrack, but it works well in the many cases when users choose an easy-to-remember password. Operating System: Windows, Linux, OS X.

For the full list of recommended open source security tools, view the full story here.