Photoshop, the most popular design & photo editor software. Graphic designers, web designers, photographers, everyone use it. The best software for compositing, digital painting, photo editing, user interface design. Endless design possibilities.
A few days ago I found a great website with keyboard shortcuts for Adobe Photoshop CC (but not only). You can find their shortcuts to other Adobe Creative Suite software as well (Adobe Illustrator, Adobe Indesign, Adobe Fireworks, Adobe Flash, Adobe Premiere and Adobe After Effects).
Photoshop shortcuts to speed up your workflow