LibreCAD Easily create and edit various types of CAD files for free -- 2D PPM, XBM and XPM formats included.
Autodesk Fusion 360 Powerful collaboration CAD editing and viewing software for sharing and modifying your 3D models with CAD and CAM projects.
Mini CAD Viewer Viewing and zooming in of DWG, DWF and SXF CAD files.