Miro

Miro is a free HD-capable video player, podcast client, and much more, that can play almost any video file and offers thousands of free internet TV shows and video podcasts.

Once you subscribe to your favorite feeds, Miro will check for and download new audio and video webcasts automatically, and organize everything into a clean, easy-to-use interface. Files can be saved forever, or will be automatically deleted after a specified number of days; users can specify how much disk space to allow, so Miro won't fill up your drive unless you want it to. Since Miro actually downloads most files to the local harddrive, they are available while you're on the go and away from an internet connection.

Free, open-source, available for many platforms

VLC

VLC Media Player, also known simply as "VLC", is a popular, GPL-licensed, free, open-source media player available for a variety of platforms, including Windows, Mac OSX, Linux, BSD, and some mobile devices. VLC uses its own plug-in system, which frees it from relying upon the codecs installed on a particular PC, which can save the user a lot of time and trouble hunting for an appropriate codec for a particular media file. VLC can play virtually all popular file formats, encoded with most popular codecs, including MP3, OGG, DIVX, XVID, MOV, AVI, MPG, MP4, FLV, and much, much more. With a variety of advanced features and a user-friendly interface, VLC is a great choice if you need or want a media player to complement or replace your current one.

Free, open-source, available for many platforms

Mediacoder

Mediacoder is a free, easy to use tool for converting video and audio from virtually any format to virtually any other. The variety of supported file types and codecs is very impressive, and the user interface makes the process as easy as possible. Mediacoder is a particularly popular free solution for users who need to convert media for playback on iPhone/iPod, PSP, MP3/MP4 players, and mobile phones that support 3GP. In addition to the standard edition of Mediacoder, there are special editions of Mediacoder, tailored to particular devices, making the process even easier.

Free

Audacity

Audacity is a popular, GPL-licensed, free, open-source audio recorder and editor available for a variety of platforms, including Windows, Mac OSX, and Linux. Audacity can be used to record audio, convert from one format to another, cut and splice audio, filter noise or add special effects, and much more.

Free, open-source, available for many platforms

GNU Image Manipulation Program

A raster editor is simply an image editor that works on a pixel basis, rather than using vector-based graphics; for example, Adobe Photoshop and Microsoft Paint are popular commercial raster editors. GNU Image Manipulation Program is a popular, GPL-licensed, free, open-source raster editor (with an unfortunate acronym) available for a variety of platforms, including Windows, Mac OSX, and Linux. Capable of simple image creation and editing to full-fledged professional photograph retouching, this is a powerful tool with a great deal of the same capabilities as expensive commercial products. With support for plug-ins, advanced scripting, and batch processing support, GNU Image Manipulation Program is great choice for a powerful raster editing tool, without the huge price tag. There is a learning curve with associated with this tool, as with any powerful raster editor, but with its large community, it is easy to find guides and help to get started.

Free, open-source, available for many platforms
Recommended for advanced users

Inkscape

A vector editor is simply an image editor that works on a vector basis, rather than using pixel-based graphics; for example, Adobe Illustrator and CorelDRAW are popular commercial vector editors. Inkscape is a popular, GPL-licensed, free, open-source vector editor available for a variety of platforms, including Windows, Mac OSX, and Linux. The developers of Inkscape are focused on being fully compliant with the XML, SVG, and CSS standards, while constantly improving this powerful tool, with many of the same features as its commercial and proprietary counterparts. Most users will not have a need for a vector image editor, but for those that do, Inkscape is a great choice. Inkscape enjoys a large user base, so some great guides and help on getting started are available.

Free, open-source, available for many platforms
Recommended for advanced users

Picasa

Google's Picasa is the standalone counterpart to their Picasa Web Albums, with many of the same features, but installed on your local machine. Picasa supports a wide variety of options for organizing, searching, and tagging digital photos, as well as editing photos as needed, while retaining the originals unchanged, just in case. A small sample of Picasa's features include: viewing, organizing, editing, revisioning, geotagging, keyword tagging, face recognition, and optional syncing online to Picasa Web Albums.

Picasa's face recognition technology is one of its most celebrated features, and unlike many other applications, it does not just detect faces in general, but recognizes the faces of individual people, and does it quite well. This powerful technology allows Picasa to process all of your photos, picking out and recognizing individual faces; once you tell Picasa the name of a person whose face it has found, it will automatically recognize that person from there onward. Instead of having to go through your photos, one by one, noting who is in which photos, Picasa can handle this automatically, allowing you easily to search and find photos of a particular person, or even photos in which two or more particular people appear together.

Free, available for many platforms

Blender

Blender is an extremely popular, GPL-licensed, free, open-source 3D graphics editor available for a variety of platforms, including Windows, Mac OSX, and Linux. Blender has many of the same features and capabilities of proprietary and commercial 3D tools, such as 3ds Max and Maya, and can be used for modeling, texturing, rigging, particle simulations, skinning, animating, rendering, compositing, non-linear editing, and creating interactive 3D applications, such as games. Most users will not have a need for this type of tool, but for those that do, Blender is a great choice; it enjoys a large user base, so even though there is a steep learning curve, some great guides and help on getting started are available.

Free, open-source, available for many platforms
Recommended for advanced users

Handbrake

Handbrake is a popular, GPL-licensed, free, open-source tool, available for a variety of platforms, including Windows, Mac OSX, and Linux, for converting DVD media to other formats for archiving or viewing on portable devices. Most users will not have a need for this type of tool, but for those that do, Handbrake is a great choice and enjoys a large user base.

Free, open-source, available for many platforms
Recommended for advanced users