Desktop Publishing:
  Gimp: Gaphics (Linux, Mac, Win)
  Gimp: Portable (Win)
  Gimp.App Images (Mac)
  Scribus Publishing (Linux, Mac, Win)
Genealogy Analysis:
  GenealogyJ: Genealogic Data-Viewer (Linux, Mac, Win)
  Geneotree: Genealogy Tree(Linux, Win)
  Gramps: Family Tree (Linux, Win) 
  Lifelines: Genealogy Tree (Linux, Mac, Win)
  PhPGedView: Your Old Ancestors(Linux, Mac, Win)
Geographic Information Systems (GIS, GPS):
  FreeGIS (Linux, Mac, Win)
  GMapCatcher: Street Maps (Linux, Mac)
  OpenStreemap: Free Geographic Data
  QuantumGIS (Linux, Mac, Win)
Graphics: CAD Software:
  Appleseed: Production Rendering (Linux)  Ares: CAD (Linux, Mac, Win)
  Blender: 3D Animation (Linux, Mac, Win)
  BRL-Cad: 3-D CAD (Linux, Win)
  Cycas 2+ 3D Architecture (Linux, Win)
  Cycles: Production Render
  DraftSight: Free Cad (Linux, Mac, Win)
  ElectricVLSI Design System (Linux, Mac, Win)
  FreeCAD: 3D Design (Linux, Win)
  Inkscape Graphics (Linux, Mac, Win)
  LibreCAD: CAD Application (Linux, Mac, Win)
  LuxCoreRender: 3-D Render (Linux, Mac, Win)
  Medusa4: CAD (Linux)
  Open Cascade: 3-D (Linux)
  QCad: 2-D Cad (Linux, Mac, Win)
  Sweet Home 3-D  Home Design (Linux, Mac, Win)
  Varkon: Parametric CAD-Tool (Linux, Mac, Win)
  Wings 3D (Linux, Mac, Win)
  Varkon 2D-3D CAD (Linux)
  YafRay Ray Tracer (Linux, Mac, Win)
Graphic Resources:
  Art4linux: Art (Linux)
  Batch Image Editor (Linux, Mac, Win)
  BirdFont: Create Fonts (Linux, Mac, Win)
  Char Tr: Mindmapping (Linux)
  Cenon Graphics (Linux, Mac)
  CinePaint (Linux)
  Coppermine: Web Album (Linux, Mac, Win)
  DIA: Drawing, Graph (Linux, Win)
  DigiKam: Photo Management (Linux, Mac, Win)
  Emesene: Webcam (Linux, Win)
  Enblend: Image Blend (Linux, Mac, Win)
  Eye of Gnome Image Viewer (Linux)
  F-Spot: Photo Management (Linux)
  Fluendo Multi Media (Linux)
  Freemind: Mindmapping (Linux, Win)
  Freeplane: Mindmapping (Linux, Win)
  Free Ruler (Mac)
  Gestalter: Vector Drawing (Linux)
  GImage View: Image Viewer (Linux)
  Gimp: Gaphics (Linux, Mac, Win)
  Gimp: Portable (Win)
  Gimp.App Images (Linux, Mac)
  Glimpse: See Gimp (Linux, Mac, Win)
  GPicView: Fast Image Viewer (Linux)
  Goh: (cf. Opencanvas) Graphics Editor (Linux)
  Gloobus: (cf. Quicklook) (Linux)
  GraphTool (Linux)
  Graphic & Design Apps: The Best (Linux, Mac, Win)
  Gthumb Image Viewer (Linux)
  Graphviz Graph Visualization (Linux, Mac, Win)
  gvSIG: GI SUser (Linux, Mac, Win)
  Hugin: Panorama GUI (Linux, Mac, Win)
Graphic Resources:
  Image Apps (Linux, Mac, Win)
  ImageGlass (Windows)
  ImageMagick: Editor (Linux, Mac, Win)
  Image Viewers (Linux, Mac, Win)
  Imagination: DVD Presentation Maker (Linux)
  imgSeek: Photo Image Viewer (Linux)
  Inkscape Graphics (Linux, Mac, Win)
  Irfanview: Fast Graphic Viewer (Win)
  Karbon14 Vector Graphics (Linux)
  Kolourpaint (Linux)
  KuickShow: Image Browser Viewer (Linux)
  Krita: Graphical Tool (Linux)
  Ksquirrel Image Viwer (Linux)
  Labyrinth: Mindmapping (Linux)
  LinuxCad Drafting (Linux)
  LyX The Document Processor (Linux, Mac, Win)
  Meshlab: Edit Graphics (Linux, Mac, Win)
  Mindmapping: Organization App (Linux, Mac, Win)
  Morevna: Anime (Linux, Mac, Win)
  Mypaint: Open Source Painting (Linux, Mac, Win)
  Nathive: Linux Image Editor (Linux)
  MTPaint: Paint Editor (Linux, Win)
  Open Clipp Art Library (Linux, Mac, Win)
  OpenMotif Graph  Interface (Linux, Mac)
  Paintbrush: Mac Paint-Like (Mac)
  Paint.Mono: Image Editing (Linux, Mac)
  Paint.Net: Image Editing (Win)
  Panorama Tools (Linux, Mac, Win)
  Pencil2D: Animation (Linux, Mac, Win)
  Photomagic (Linux)
  PhotoQt (Linux, Win)
  PixelPost: Photoblog (Linux, Mac, Win)
  Picasa: Photo Management (Linux, Win)
  PicView: Picture Viewer (Win)
  Pinta: Image Editor (Linux, Mac, Win)
  Piwigo: Web Album (Linux, Mac, Win)
  Ptex: Disney Animation (Linux, Mac, Win)
  QIV: Quick Image Viewer (Linux)
  Rapid Photo Downloader (Linux, Win)
  Rawstudio: Photo Converter (Linux)
  RawTherapee: Photo Converter (Linux)
  Refocus: Pluggin for GIMP (Linux, Mac, Win)
  Seashore: (cf.  GIMP)  Image Editor (Mac)
  Simple Scan: Scanning (Linux)
  Shotwell  (cf. Picasa) Photo Organizer (Linux)
  Skencil: Vector Drawing (Linux, Mac)
  SketchUp 3D (Linux, Mac, Win)
  Sk1 Vector Graphics  Editor (Linux, Mac, Win)
  Sodipodi: Vector Drawing (Linux, Win)
  SWFTools: Graphic Tools (Linux, Win)  
  Sweet Home 3-D  Home Design (Linux, Mac, Win)
  SV-Editor: Drawing Editor (Linux)
  Synfig: 2D Animation (Linux, Win, Mac)
  Thuban: Geographic Viewer (Linux, Win)
  TuxPaint: Children (Linux, Mac, Win)
  UFRaw: Manipulate Images (Linux, Mac, Win)
  Viewnior: Elegant Image Viewer (Linux)
  Unshake Refocus Photos (Linux, Win)
  VYM: Mindmapping-Line (Linux)
  W3C: Web Graphics (Linux)
  Xara Graphics (Linux, Mac)
  Xmind: Mind Mapping (Linux, Mac, Win)
  Xnview (Linux, Mac, Win)
  Xpaint: Paint Editor (Win)
  GQview: Image Browser (Linux)
  Xfig (Linux)
  ZGV: Image Viewer (Linux)