.NET

[#1]

Is there a way to Update drawings such as changing layers, etc without creating a dll and a commanmethod?

I would like to write a VS app that would make changes directly to the drawing and not have to use the commandmethod approach.

[#2]

You would have to pay for RealDWG or use openDWG

http://www.opendwg.org/

http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=770257

[#3]

I have no experience with this at all, but I want to get into it, & I have found this swamp article with intersting info about ObjectDBX

http://www.theswamp.org/index.php?topic=39365.0

[#4]

When you are linking into AutoCAD from an external program you would use ObjectDBX to access the properties of the object. However you still have to have a copy of AutoCAD running.