ANIMATION SOFTWAREBlender 3D: Blender 3D is a high-quality, robust animation program with a steep learning curve and the ability to create commercial-quality 3D animations. The software is completely free, with extensive documentation available online for free.
Pencil (2D): Pencil is a free 2D animation program intended to make traditional hand-drawn animations possible. Animations are drawn on individual 'pages', and then compiled together in a digital flipbook of sorts.
KPovModeler: KPovModeler is a composition/modeling program for making POV-Ray scenes: an excellent addition to Blender 3D, and intended KDE.
Stopmotion: Stopmotion is a program that allows you to capture and/or combine photos together to create a smooth stopmotion animation video. Not only works well for claymation and similar, but can also be used to create timelapse videos.
Synfig (2D): Synfig is a free 2D animation software package that states "two-dimensional animation has long been the domain of proprietary software...Synfig, a free software/open source tool for producing feature-film quality animation with fewer people and resources."
Anime Studio 5 (2D)($199.99): Anime Studio 5 is a powerful commercial application for creating 2D animations with the ability to import/export OBJ files, special effects scripting, layered animation, vector animation, and advanced timeline controls.
AUDIO SOFTWAREAudio CD Extractor (ripper): Available through Add/Remove Applications, Audio CD Extractor (previously known as Sound Juicer) is an easy to use CD ripper, intended to make copying music CDs fast, simple, and straight-forward.
Audacity (recorder): Audacity is an excellent, free digital audio recorder/editor for nearly all audio types. It can record multiple channels, split channels, merge audio, and a wide array of other features. Supports recording from both line-in and sound card.
Sound Converter: This is an application for GNOME that accepts a wide array of different audio formats and converts them to mp3, wav, flac, or ogg.
Last Exit (player): Last Exit is a standalone player for Last.fm that allows you to add specific stations, search for stations, choose a neighbors station, or browse. You can set preferences, password protect it, and save changes.
Hipo iPod Management Tool: If you have an Apple iPod, the Hipo iPod Management Tool is an invaluable program that allows users to manage their device.
Utube-Ripper: Have you every come across a video on YouTube you wanted to save to your hard drive? With Utube Ripper, you can download and save either the entire video, or the audio only. Very sleek and easy to use.
Freqtweak: According to Add/Remove Applications, “FreqTweak is a tool for real time audio spectral manipulation and display. It provides several algorithms for processing audio data in the frequency domain and a highly interactive GUI to manipulate the associated filters for each. It also provides high resolution spectral displays.”
VIDEO SOFTWAREVLC: VLC is arguably the most popular video player on any operating system. It supports nearly every video type available, offers the ability to change audio settings, choose audio channels (headphones, full bass, etc.), change video aspect ratio and more. The program is lightweight and easy to use.
AcidRip: AcidRip is a simple, straightforward tool for copying a DVD to a digital video file, with codecs such as XviD, x264, MPEG, and more available. It allows you to control file size, audio settings, quality, cropping, etc.
Avidemux: Avidemux is an excellent video editing application. You can add filters, meticulously manipulate audio and video, combine VOBs, combine videos, and much more.
DVD::RIP: While AcidRip is the best tool to use if you want to create a video straight from a DVD, DVD::RIP is ideal if you want to convert an ISO or VOB files. Simply start the program, load the file, and then choose the video settings and transcode to an AVI or other file format.
Gnome Subtitles: Edit, add, and manipulate subtitles on a video using this free program.
iriverter: iriverter is a frontend for mencoder that makes it simple to convert videos for a wide array of portable video devices, including the Creative Vision M and iRiver players. Single and batch conversions can be done.
Wink: Wink is a free video program for creating video screencasts; an excellent program for creating video tutorials and presentations, with the ability to add explanation boxes to the video.
XBMC Media Center: XBMC is an award-winning media center for multiple platforms, and is fully supported on Ubuntu. The program is sophisticated and high-quality, and is a top-notch media player that can organize and play videos, music, and photos, including previews and album covers.
GRAPHICSGIMP: GIMP is the Linux alternative to Adobe Photoshop. It is an advanced image authoring/editing program with an animation engine and a wide array of plugins/filters/brushes. It can do nearly everything Photoshop can do, but does require one to learn it proficiently in order to exploit it's features.
Comix: Comix is a comic book viewer for Linux. It is high-quality, works smoothly, and offers all the necessary components for viewing digital comics, including double-page support, zoom, rotation, mirroring, fullscreen mode, fit-to-screen mode, image enhancement, image quality toggle, and bookmarks.
Inkscape: Inkscape is a sophisticated vector graphics program similar to Adobe Illustrator.
QCaD: QCaD is as close to autoCAD as you can get on Ubuntu. It offers the ability to create and files, with support for autoCADR and similar files
OFFICExPDF: xPDF is a suite of PDF tools, including a lightweight viewer with support for standard, Truetype, and Type 1 fonts, conversion tools for converting PDFs into different formats, and support for multiple languages.
AbiWord: Abiword is a popular, lightweight and yet sophisticated word processor that works very well on Linux. It is best for those who need to create documents, but don't require a massive amount of features
OpenOffice Writer: OpenOffice Writer is a large, high-end word processor. It works well on Linux, and has all the features you could possibly need. If you're looking for a complete alternative to MS Word, Writer is your best option.
OpenOffice Spreadsheet: Very similar to MS Excel.
OpenOffice Presentation: Alternative to MS PowerPoint.
OpenOffice Impress: Alternative to MS Publisher.
KAddressBook: KAddress is a personal contacts/address manager.
KOrganizer: KOrganizer is a calendar and scheduling app with the ability to track important dates, add notes, and export to industry standard files. GnuCash: GnuCash a finance management software suitable for both personal and business use. It can support major file types, such as Quickbooks files, and tracks multiple accounts, constantly calculating new balances and tracking everything needed, including investments and expenses.
xCHM: xCHM is a CHM HTML file viewer, suitable for viewing large HTML ebooks and files saved in the CHM file type.
UTILITIESGPSDrive: A navigation system designed to work with a GPS receiver. Offers the ability to zoom and display maps downloaded or generated as needed via OpenStreetMap.
Gnome Partition Editor: The Partition Editor allows you to easily manipulate partitions with support for multiple file structures.
Virtual Box OSE: Virtual Box is a virtual machine application, allowing you to run different OS's inside your Linux machine.
ClamAV: Clam AV is an anti-virus software app for Linux, and works very well.
Gmount-ISO: Gmount is a frontend for a Terminal command that allows you to easily mount a DVD or CD ISO image.
INTERNETOpera: Opera is a lightweight browser with wide support and a customizable launch page.
Mozilla Firefox: Firefox is the most popular Internet browser for Linux, offering stability, wide support, and a massive amount of plugins.
Thunderbird: Thunderbird a popular email client from the Mozilla line of Internet applications. It offers multiple account access, IMAP and SMTP, password protection, address books, and more.
SeaMonkey: SeaMonkey is based on Firefox Internet browser, but is more stable.
Evolution:Evolution is another email client, but appears very similar to Microsoft's Outlook.
Pidgin IM: An instant messaging client that support AIM, ICQ, Yahoo! IRC, Zephyr, Gadu, Groupwise, SIMPLE, SILC, Sametime, Napster, MSN, and Jabber.
gFTP: gFTP is a file transfer protocol app for Linux offering support for a wide array of uploads and downloads.