Open Source For MultiMedia
GIMP
http://www.gimp.org/
Windows http://gimp-win.sourceforge.net/
GimpShop http://gimpshopdotnet.blogspot.com/
GIMP is the GNU Image Manipulation Program. It is a freely distributed piece of software for such tasks as photo retouching, image composition and image authoring. It works on many operating systems, in many languages.
AudaCity
http://audacity.sourceforge.net/
http://audacity.sourceforge.net/help/faq?s=install&item=lame-mp3
Install MP3 For Audacity
Audacity is free, open source software for recording and editing sounds. It is available for Mac OS X, Microsoft Windows, GNU/Linux, and other operating systems.
TerminatorX
http://terminatorx.org/
TerminatorX is a realtime audio synthesizer that allows you to "scratch" on digitally sampled audio data (*.wav, *.au, *.ogg, *.mp3, etc.) the way hiphop-DJs scratch on vinyl records. It features multiple turntables, realtime effects (buit-in as well as LADSPA plugin effects), a sequencer and MIDI interface - all accessible through an easy-to-use gtk+ GUI. This software is designed to run under Linux, FreeBSD and the like.
Sweep
http://www.metadecks.org/software/sweep/
Sweep is an audio editor and live playback tool for GNU/Linux, BSD and compatible systems. It supports many music and voice formats including WAV, AIFF, Ogg Vorbis, Speex and MP3, with multichannel editing and LADSPA effects plugins.
EcaSound
http://www.eca.cx/ecasound/
Ecasound is a software package designed for multitrack audio processing. It can be used for simple tasks like audio playback, recording and format conversions, as well as for multitrack effect processing, mixing, recording and signal recycling. Ecasound supports a wide range of audio inputs, outputs and effect algorithms. Effects and audio objects can be combined in various ways, and their parameters can be controlled by operator objects like oscillators and MIDI-CCs. A versatile console mode user-interface is included in the package.
PureData
http://www.puredata.org/
PD (aka Pure Data) is a real-time graphical programming environment for audio, video, and graphical processing. It is the third major branch of the family of patcher programming languages known as Max (Max/FTS, ISPW Max, Max/MSP, jMax, etc.) originally developed by Miller Puckette and company at IRCAM. The core of Pd is written and maintained by Miller Puckette and includes the work of many developers, making the whole package very much a community effort.
NetPD
http://www.netpd.org/About
netpd is a project based on the software puredata. its intention is to create an environment for electronic musicians and give them the opportunity to jam with each other in realtime, connected over the internet or a LAN.
Blender
http://www.blender.org/
Blender is the free open source 3D content creation suite, available for all major operating systems (Windows and Linux) under the GNU General Public License.
Ardour
http://ardour.org/
Ardour is a digital audio workstation. You can use it to record, edit and mix multi-track audio. You can produce your own CDs, mix video soundtracks, or just experiment with new ideas about music and sound.
Inkspace
http://www.inkscape.org/
Inkscape is an Open Source vector graphics editor, with capabilities similar to Illustrator, Freehand, CorelDraw, or Xara X using the W3C standard Scalable Vector Graphics (SVG) file format. Supported SVG features include shapes, paths, text, markers, clones, alpha blending, transforms, gradients, patterns, and grouping. Inkscape also supports Creative Commons meta-data, node editing, layers, complex path operations, bitmap tracing, text-on-path, flowed text, direct XML editing, and more. It imports formats such as JPEG, PNG, TIFF, and others and exports PNG as well as multiple vector-based formats.
OpenMovieEditor
http://openmovieeditor.sourceforge.net/HomePage
Open Movie Editor is designed to be a simple video editor, that provides basic movie making capabilities. It aims to be powerful enough for the amateur movie artist, yet easy to use.
Mplayer
http://www.mplayerhq.hu/
MPlayer is a movie player which runs on many systems (see the documentation). It plays most MPEG/VOB, AVI, Ogg/OGM, VIVO, ASF/WMA/WMV, QT/MOV/MP4, RealMedia, Matroska, NUT, NuppelVideo, FLI, YUV4MPEG, FILM, RoQ, PVA files, supported by many native, XAnim, and Win32 DLL codecs. You can watch VideoCD, SVCD, DVD, 3ivx, DivX 3/4/5 and even WMV movies.
VideoLan
http://www.videolan.org/
VideoLAN produces free software for video, released under the GNU General Public License.