Please note that the content of this book mainly consists of articles that are available online from Wikipedia or other free sources. Adobe Illustrator is a vector-based graphic design and drawing program. It was developed and marketed by the California software company Adobe Systems. Originally created for the Apple Macintosh, Adobe filled the gap between complicated CAD programs and inflexible, imprecise pixel-based painting programs with Illustrator. For the first time, graphic user software used Bézier curves to describe graphic and geometric objects. From the beginning, the Illustrator file format (.ai) was based on PostScript, allowing for direct data transfer in this format to a printer.