QuickLook (MacOS Leopard only) is an Apple technology used to show the contents of a file without opening the file or even having the application the document was created in. DocHaven uses the same technology and the same keystroke (press the spacebar to open or close the QuickLook window) to view the contents of the file.
Options
Drag a file, hard drive or server from the Finder on to the QuickLook window to display it.
Drag the QuickLook window resize box to see the document contents in more details.
Arrow down in the DocHaven window while the QuickLook window is open to show the contents of other files in the QuickLook window