Download DWGCompareX
The control only works with IE directly, to work with Firefox or Chrome, please install the ActiveX manually and use the ff-activex-host, IE Tab Plus or other add-ons to support the ActiveX control.
IE Tab:
https://addons.mozilla.org/en-US/firefox/addon/ie-tab-2-ff-36 ff-activex-host:
http://code.google.com/p/ff-activex-host/
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