The essential programs that every Linux user needs

Following the success of our 25 killer apps for Linux post, we've dug deep to find the 20 must-have apps you should get your hands on today. Believe us when we say that for Linux users, they're indispensable.

Graphics

LightZone 3.4
www.lightcrafts.com/linux
This powerful photo editing tool enables you to adjust the lighting attributes for any photo. Its main strength is that it uses a 'smart' editing design, in which there's typically one slider to adjust exposure settings, high dynamic range light sources, add sepia tones and make hundreds of other tweaks to a photo to improve it ? or just make it look more creative. With dark photos, LightZone works wonders by enhancing the tones in the photo and brightening every pixel without giving the photo a washed-out look. The beta is free to try, but the final download package costs ?100.

Qtfpsgui
https://qtpfsgui.sourceforge.net
Long-time Linux users know that the key advantage to the operating system is that a programmer can decide to make one particular tool ? usually something he or she needs in a toolbox ? and release the application into the wild. Qtfpsgui is just such a tool. It enables you to experiment with high-dynamic range lighting in a photo or 3D image that might be used in a game or 3D world. The options for controlling HDR lighting are simple: adjust a slider for gamma correction, load a tonal mapping tool to adjust light sources and other variables. Then, save your work for modelling in a 3D world.

Hugin
https://hugin.sourceforge.net
Experimenting with photography can lead to some wondrous results. Hugin is a panorama photo editor that can stitch your photos together. The process works like this: when taking photos, you position the lens for each successive shot so that the right side of the current photo lines up with the left side of the next photo ? you turn to the right each time you take a new shot. You don't have to be exact, since Hugin can stitch the photos together quite well, although a tripod certainly helps.

Multimedia

Renoise
www.renoise.com
Far beyond the simple mechanics of recording a sound, making an audio clip and sharing it with the world, this powerful music production studio is intended for those who want to adjust the fine frequencies of each audio track in a new composition, and don't want to get bogged down with the 'happy palette' approach of a tool such as Apple Logic Pro. Even though it runs on Linux, it supports the VST instrument libraries that began life in Windows.

There's a built-in sampler that enables you to create unique sounds, then add them to your audio timeline. A pattern editor helps you take those new sounds and make a recurring sequence. Sliders for mixing the music (panning left or right, adding EQ and changing the volume) help you created the finished work

CeeMedia Movie Catalog
https://ceemedia.sosdg.org
Like Alexandria, the single-purpose utility program CeeMedia is ? as the name implies ? a cataloguing utility for the movies you either own or have seen (or want to see). It's an intriguing program because it enables you to add a large amount of detail about each movie, including cast and crew, a plot summary and even a mini-review.

We think a good next step in the development of CeeMedia would be to form some kind of social networking feature, so users can exchange movie ratings and reviews ? similar to what Flixster.com does today. As it stands, CeeMedia is essentially a front-end database for all your video entertainment and it excels at that very specific function.

Alexandria
https://linux.softpedia.com/get/Desktop-Environment/Tools/Alexandria-3488.shtml
If your office library is overflowing with books, try Alexandria, a cataloguing utility that makes it easy to scan through book covers, track which books you have loaned out or those you might need to discard because they're just taking up space. A good source for book covers is Amazon.com, but be sure to click the image for the larger version.

Then, just save it to a folder and load the image into Alexandria. You can search quickly for book titles and authors, but the main purpose of Alexandria is just helping you remember which books you own and which one you want to read next.

TuxGuitar
www.tuxguitar.com.ar
Creating tabs for guitar ? the notes and instructions that help other guitar players learn the song ? can be a difficult task. Usually, it requires using a font in OpenOffice.org and handdrawing the tablatures, or using an expensive music composition program that provides a hundred features in addition to basic tab creation.

TuxGuitar is just for making tabs: it dispenses with any kind of linear sequencing and recording features and provides a way to make the tabs for any song. You can adjust tempo, note duration, signatures, triplets, and add effects such as tremolo and bends to the music.

Jokosher
www.jokosher.org
Most Linux users already know about Ardour, the powerful (but slightly confusing) multi-track audio recorder. (We're not ready to call it a digital audio workstation quite yet.) Jokosher is a much more streamlined track recorder for those who want to record their own demo tapes.

It has few features for creating loops or using files generated from a piano connected to your PC, but it does enable you to add audio files directly into the same interface in which you're recording live instruments.

Productivity

www.sagemath.org
Wolfram Research's Mathematica is still the clear leader in "scientific computing" software for end users and the education market. The program costs several thousand dollars and there's a Linux version available, but you can get by just fine with Sage, an open source equivalent. We found Sage to be a little complex to install: it wouldn't even work with one of our Ubuntu laptops and has a few unheralded dependencies, such as Latex.

Once Sage is up and running, the tool has a number of features for analysing advanced theories, cryptography and calculus. There's an online demo for Sage that enables you to try the software before installing it at www.sagenb.org.

Dia
www.gnome.org/projects/dia
Like the more mainstream drawing tool Visio (which runs only in Windows), Dia is designed for basic flow-charts to make a point about a complex problem or plan. It's a little more freeform than Visio because it doesn't quite have the same stock library of icons and pictures. The basic drawing apparatuses are all here: arrows to point out the decision tree, several shapes to add to the diagram and annotation features with support for many fonts and formatting treatments.

The program shines brightest when you use it for UML (unified modelling language) diagrams that show how an application development will progress, and adding colour to these utilitarian drawings can liven them up. Dia has good community support, but we think they should be up to a version 1 by now.

VariCAD 2008
www.varicad.com
Complex CAD programs usually cost an arm, a leg and a spleen, but VariCAD is a stark departure from the usual pricing schemes, which typically run into the thousands. For about ?300, the program mirrors the features found in AutoCAD, supporting many of the same file formats, such as STEP and DWG, and vast libraries of existing objects (most designed for mechanical engineering).

It also has an interface that tends to put every icon and option right on the main screen, where they're just a click away. This is helpful for serious designers because it means no hunting around for that one hexagonal pen tool.

Diversions

www.teeworlds.com
Who says a shooter has to be bloody and violent? TeeWorlds is a cross between Quake and Joust (a match made in heaven), in which you run around a platform-jumping level shooting other online players. It has power-ups and various above and below-ground maps, objects to impede your path and enable the other players to snipe you from a distance, and cartoon-ish graphics. This game ? which used to be called TeeWars ? is now open source; originally it was a more commercial endeavour. It's also highly addictive; a unique game that blends two unique gameplay styles.

The Sims Carnival
www.simscarnival.com
We've included one online game portal to show that there are hundreds, if not thousands, of games available to the Linux community from a browser, regardless of whether they make a Linux version. One of the newest is The Sims Carnival, which features a slew of arcade games, puzzles and even adventure games. What's most interesting about Carnival is that other users create the games for you to play, so it's an excellent introduction to the fundamentals of programming: gameplay, graphics, design, testing.

Cuyo
www.karimmi.de/cuyo
This Tetris knock-off works because it's so simple and finally dispenses with the 3D bricks. In their place, Cuyo presents cartoonish smiley faces that plunge down into a grassy knoll. In later stages, the game gets horrendously difficult as you try to colour-match the characters and form a chain of faces, some of them falling at different rates, others causing nearby faces to explode.

Another twist is that you sometimes have to form a row of smiley faces diagonally before they'll explode and sometimes a descending smiley will change colour, so you have to be quick to react to the new variables.

Stellarium
www.stellarium.org
Google is well-known for making sky-mapping software Google Sky, but Stellarium is an open source equivalent that's gaining traction with good community support and an interface that emphasises stargazing over traditional (and complex) planetarium features, such as azimuthal grids and scripting coordinates.

The program actually has most of the features in Google Sky, including the star grids ? which enable you to find as many as 600,000 stars ? but first it just shows you a wide open perspective of the sky to encourage creativity and experimentation.

Warzone 2100
www.wz2100.net
Warzone 2100 is based on a real-time strategy game developed by Pumpkin Studios way back in 1999. In 2004, the giant publishing house Eidos Interactive released the source code into the public domain and Warzone 2100 was born.

Gameplay follows the traditional mechanics of Command & Conquer, with heavy resource building and gang-rush tactics, using a graphics engine that's definitely showing its age. Yet Warzone 2100 is free and has a much deeper tree structure ? with as many as 400 technologies to research and a branching unit customisation structure, three campaigns and 24 instant action maps.

Development

Bluefish
https://bluefish.openoffice.nl
Freshly minted as a version 1.0 product, Bluefish is a powerful text editor for programmers. Billed as "extremely lightweight", the program uses about half the memory of more well-known editors, such as Quanta, so it could run just fine in a lightweight distro ? for example, Fluxubuntu ? or alongside programming environments such as Eclipse. It also loads files quickly: in a test, we opened ten HTML files in almost the blink of an eye, even though they were fairly complex.

Adobe Flex Builder Public Alpha
www.adobe.com/products/flex
Finally! This development framework for Eclipse ? it works as a plugin ? enables you to create web apps without even being connected to the web, like Google Gears. The emphasis is on easy scripting to develop a rich Web 2.0 app as quickly as possible, using the highly portable MXML language, intuitive UI design tools and support for open standards.

Salasaga
www.salasaga.org
Even though Adobe has recently opened up with its Labs initiative and supports Linux with more and more of its utility computing products (such as Flex and the Air platform), it's still nearly impossible to find versions of its main productivity apps that runs on Linux, such as Dreamweaver or Fireworks. Salasaga makes up for this deficiency by enabling you to make animated Flash movies using the native SWF format, and will eventually support Ajax for fully interactive content in

Octave 3
www.gnu.org/software/octave
This development platform is intended to aid programmers with computational problems ? including non-linear equations and polynomials, working with differential-algebraic equations and other complex maths problems ? through its own custom-built programming interface.

The main improvement in version 3.0 is better interoperability with Matlab, the data analysis and visualisation tool that helps programmers with complex workflows in high-end computing development.