Gerber Viewer is a viewer for Gerber files. Gerber files are generated from PCB CAD system and sent to PCB manufacturers as basis for the manufacturing process. The standard supported by gerbv is RS-274X. gerbv also supports drill files. The format supported are known under names as NC-drill or Excellon. The format is a bit undefined and different EDA-vendors implement it different. gerbv is listed among Fedora Electronic Lab packages.