DWG Diff - Drawing Differencing Tool.

DWG Diff is a simple tool that displays the differences(and commonalities) between two drawings.

Features
Compares all drawing entities in the selected drawing space (Model,Layout)

Compares all other drawing structures such as: Layers, Blocks, Text Styles, Layouts, etc.

Compare dwg drawings from R12 to 2007.

Comparative output can be saved as dwg, dxf, pdf.

Free software provided by WireCAD

Requirements

Windows 2K, XP, Vista, Win7
Works natively on 64 bit machines
RAM: 512+ megabyes
Recomended Hard Drive space: 170 megabytes
1024x768 32 Bit capable monitor/graphics
(widescreen or dual screens are helpful)