Commonly used Graphic Design Applications
When it comes to programs used by a Graphic Designer, the application choices are quite restricted. Adobe is the king when it comes to applications for the designer. They have (almost) complete market share of all things digital.
Adobe the King of Print Based Design Applications
A print based designer will heavily use programs such as Adobe Photoshop, Adobe Illustrator and Adobe InDesign for the majority of their work, typically outputting to programs like Adobe Acrobat and Distiller for PDF creation. So whether it be a poster, book, business card, letterhead and so on, these are the applications that would be used.
All of these programs cross over to a certain extent and serve a purpose throughout the design process. I know if I’m designing something for client, typically I’ll use at two or three of the above programs. The reason being that some of the programs simply do a better job than others depending on the desired outcome.
GIMP (OSX, Windows, Linux)
Inkscape (OSX, Windows, Linux)
Quark (OSX, Windows)
Scribus (OSX, Windows, Linux)
Web Based Graphic Design Applications
Let’s switch to digital / web design for a moment. This is where Adobe doesn’t have it their own way quite as much. Yes, a designer may create assets in Adobe based programs such as Photoshop and Illustrator (for website design, application design and so on) and Adobe Fireworks has it’s own loyal following, but to create the website is usually done using a different app altogether. Dreamweaver (another program by Adobe) doesn’t have the same strength in the coding world that other Adobe applications do in the Print world. The coder will usually have a program of choice, whether it be Coda (like I use) TextWrangler or Sublime Text for example. The choice is also restricted based on the operating system, typically Windows or OSX will dictate what applications can be used.
Hopefully that gives you a better insight as to what programs are used. This is taken from a very broad perspective, whether designers may also use specialty programs like Cinema 4D, 3D Studio Max, Quark XPress and so on, based on what they’re required to do and their skillset.