Ghostscript is a processor for PostScript and PDF files. It can rasterize these files to a wide variety of printers, devices for screen preview, and image file formats. Since applications tend to prepare pages for printing in a high-level format such as PostScript, most Unix users with low-level bitmap printers, such as inkjets, use GhostScript as part of the printing process. In addition, Ghostscript is capable of converting PostScript files, functionality comparable to Adobe Acrobat Distiller, but on the command line. In addition, Ghostscript is used for file import and viewing by a great many other applications, including xv, ImageMagick, gimp, and xdvi. Several GUI wrappers for viewing PostScript and PDF files exist, including GSview, ghostview, gv, ggv, and kghostview. This is far from a comprehensive list.
hp2xx is a versatile tool to convert vector-oriented graphics data given in Hewlett-Packard's HP-GL (a.k.a. HPGL) plotter language into a variety of popular both vector- and raster-oriented graphics formats. The various supported output formats include Encapsulated PostScript (EPS), PCX, IMG, and several formats intended to facilitate the generation of graphics within TeX documents. In addition, hp2xx output is printable on the HP Laserjet/Deskjet printer series, and it may be used as a HP-GL previewer on many platforms, e.g. X11 and DOS (VGA).
GSview is a graphical interface for Ghostscript, an interpreter for the PostScript page description language used by laser printers. For documents following the Adobe PostScript Document Structuring Conventions, it allows selected pages to be viewed or printed. GSview requires Ghostscript 7 or later.
flscan (Fast Light Scan) is a new frontend for the SANE libraries and dlls. It can rotate images by 90° both clockwise and counter clockwise, flip images both vertically and horizontally, correct the horizontal aspect of the image, save aquired images in JPEG or in PNG format, let you view images even at full size after they've been acquired, and potentially supports all the SANE backends.