Quick View Plus 11 includes a preview handler that works within Directory Opus (and newer versions of Windows Explorer and Outlook).
Simply installing Quick View Plus 11 Standard (or above) will add its viewing abilities to Directory Opus if you are on Windows Vista, Windows 7 or above. (Windows XP users can still benefit, with an extra step. See below.)
Notes & Caveats (updated September 2011):
- Windows XP: Quick View Plus 11 does not install its preview handler on Windows XP; however, the DLLs it installs seem to work with the Opus MultiView plugin.
- 32-bit: Avantstar support Quick View Plus on 32-bit editions of all current versions of Windows.
- 64-bit: Avantstar support Quick View Plus on 64-bit editions of Windows 7. (I found it worked okay on 64-bit Vista as well, but it's not officially supported.)
- QVP editions: Quick View Plus 11 comes in two editions: Standard and Professional. The Standard edition is all you need if you just wish to view files within Directory Opus.
- QVP Trial version: Trial versions of QVP may not install/enable the preview handler, and so may only let you see how well the viewers handle different file formats outside of Opus and Explorer. You may not be able to test the viewers inside Opus until using the full purchased version. This seems to have changed back & forth over the years, so may vary.
(Thanks to Michael Kenward, Jon Potter, Plunder and Avantstar themselves for their help discovering the info above. Thanks also to Ron Hirsch whose quest for a way to view Word Perfect files in 64-bit Opus led us here.)