Comic Book Archive file or ComicBook Reader File files. Occasionally is a ZIP, RAR, or more rarely TAR file of images with the file extension renamed to .cbz ,.cbr and .cbt respectively for the purpose of viewing the images in sequence with an image viewer and simplifying file maintenance. The idea was made popular by the CDisplay image viewer. CBZ/R/T files typically contain PNG or JPEGGIF, BMP, and TIFF are seen, but the PNG format is a better replacement for each of them for various reasons. Their contents can be extracted by any utility that can read ZIP, RAR and TAR files. CBZ/R files can easily be created by storing (not compressing) any group of images with file archivers on .zip or .rar file formats, and later changing the extension to .cbr for .rar files and to .cbz for .zip files. CBT files derive from tar, tar.bz2 and tar.gz and are rarely used. The first comic produced specifically for this format was Saturn Knight, released in August 2006 by Jim Shelley and Pierre Villeneuve.