GhostScript is a PostScript and PDF interpreter that can turn
PostScript and PDF files into raster image files (e.g., RISC OS
sprites) and that can turn PostScript files (e.g., those produced by
the RISC OS PostScript driver) into PDF files. PostScript and PDF are
industry-standard page description languages defined by Adobe that
describe the appearance of documents with multiple pages containing
text, bitmap images and vector graphics.