PCX format is one of the most usable graphic formats. Originally, it was designed by Zsoft for PC Paintbrush MS-DOS. Hence, it is also known as PC Paintbrush format. Zsoft signed a deal with Microsoft, and as a result, the latter was entitled to use PCX format with other products, including Microsoft Paintbrush for Windows (Microsoft Paintbrush program is delivered with each copy of MS Windows). PCX files are used for graphic data storage and exchange in desktop publishing systems. Image data is encoded with the help of one of the RLE algorithm variants.