Yes to both questions. GStarICAD's native file format is .DWG, so when you open an existing Autodesk AutoCAD file (2.5 to 2008), there's no file conversion and no data loss. GStarICAD also provides a full compatibility with AutoCAD Command Line, menu (.MNU) and script (.SCR) files, hatches, fonts and true type fonts-Complex linetypes, Multiline Text, Lightweight polyline, Draw commands,  Audit & Recover as well as AutoLISP and ADS. That means you can get to work immediately using the AutoCAD files, commands and applications you rely on.