Humbly claiming to be "the absolute best SPAM fighting weapon that
the world has ever known," ASSP is short for "Anti-Spam SMTP Proxy"
Server. While it takes a little work to get it up and running at
first, it doesn't require a lot of maintenance, and the site wiki
includes extensive help on configuring the app so that it works for
you. Operating System: Windows, Linux, OS X.
Available as an Outlook add-on, as a Thunderbird extension, or as a
stand-alone proxy, Spamato uses multiple filters to separate junk
mail from the stuff you actually want to receive. Unlike some
anti-spam tools, it also lets you see why a message gets classified
as spam and adjust your settings as necessary. Operating System:
Windows, Linux, OS X.
"Open Source Anti-Spyware
Nixory will quickly scan your system and remove any malicious
cookies from Firefox. Unlike some similar apps, you can use it
alongside other anti-virus or anti-spyware applications without
first disabling those systems. Operating System: Windows, Linux, OS
X. Open Source Anti-Virus/Anti-Malware
One of the best-known open-source security projects, ClamAV
provides e-mail virus and malware scanning for Unix-based systems.
Its owners update its prodigious virus database several times each
day to provide up-to-the minute protection from evolving threats.
Operating System: Linux."