DWG-Viewer
Autodesk Viewer (online), DWG TrueView, Design Review
The latest updates and service packs can be found on the following Autodesk download pages:
AutoCAD, AutoCAD Architecture, AutoCAD Mechanical
Older updates and service packs can be found on the following Autodesk download pages:
AutoCAD Architecture 2016 Service Pack 1
AutoCAD Mechanical 2016 Service Pack 1
AutoCAD Architecture 2015 Service Pack 2
AutoCAD Mechanical 2015 Service Pack 2
AutoCAD Architecture 2014 Service Pack 1
AutoCAD Mechanical 2014 Service Pack 1
AutoCAD Architecture 2013 Service Pack 2