Pixel Art Studio - A purpose-built drawing tool for pixel artists
CSS Sprite Generator - A tool for generating image sprites and CSS for your web site.
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
SpritePad - The easiest way to create your CSS sprites
Pixel Art to CSS - Draw and animate pixel art, export the results to CSS
SpriteSheep - SpriteSheep lets you easily and visually generate CSS sprite sheets and CSS code with all sprites...