Best Free Programs for Macs

Free as in Freedom

There are two types of free software.  Those that are open source (free as in freedom) grant you access to both the software and the source code (the building blocks of the software).  This allows anyone to improve the software.  The second type provide the software for free (free as in cookies) but don't provide the source code.  These programs, often called freeware, frequently have restrictions concerning who can use the software and how many licenses you can have before you have to pay a price.  The following is an alphabetical list of open source programs that I often recommend to my clients.

• Audacity - Audacity is a sound editing program.  If you need to convert something from .wav to .mp3, make a song louder, or just cut out the 10 most important seconds of a recording, this is the program for you.
• Blender - Blender is a 3D modeling program, like 3D Studio Max or Maya.  If you are a 3D graphic artist and don't have $4,000 to drop on proprietary software, you'll definitely want to give Blender a try.
• Camino - Camino is made by the same people who bring you Firefox, but it is better integrated into the Mac system.
• ClamXav - ClamXav is a simple anti-virus program.  It does not have a real-time scanner, meaning that it doesn't scan every file when you open it.  Don't be fooled by what you hear on television.  Macs are some of the most vulnerable systems on the internet right now.  You definitely want to have an anti-virus solution installed.
• GIMP (Gnu Image Manipulation Program) - GIMP is an Adobe Photoshop replacement.  It's not quite up to par if you are a professional graphic editor, but for the home user it does about everything you need.  (I should warn you that the interface is a little clunky.  Check out the online documentation if you have any questions.)
• OpenOffice - OpenOffice is a complete office suite, a la Microsoft Office.  It uses the international standard Open Document file format, which will probably eventually be adopted by everyone, including Microsoft Office (although they are fighting it every step of the way).
• Thunderbird - Thunderbird is a free email client originally created by the same organization that brings us Camino.  Thunderbird has excellent spam filtering capabilities.  It also has a large collection of optional addons.  My favorites are Lightning (an integrated calendar), Display Mail User Agent (shows the program that was used to write the emails you receive), Enigmail (digitally signs and encrypts emails, requires MacGPG), and SyncKolab (synchronizes contacts, tasks, and calendars between multiple computers).
• Untangle - Untangle is a virtual gateway appliance that filters your internet connection, blocks bad websites, porn, viruses, adware, spyware, phishing, and a whole lot more.  It can run either as a virtual machine inside of an existing Windows computer or as a stand-alone Linux installation.  For large networks I would recommend running the stand-alone version for performance reasons, but you might be able to get away with it on Windows on a home network.

Free as in Cookies

There are some programs that aren't open source but are free to use (at least under some circumstances).  There is currently nothing on this list for Macs (all the good stuff appears to be open source).  However, I'll keep this section as a placeholder in case something comes along.