Interesting. I like the speed!

Some of them you're probably aware of, but here goes:

• The program tries to open PDFs and BMP images, but displays just a blank black box for both.
• When opening an image too big for my screen, and I'm not telling it to shrink images to fit, it opens it up in full size, but there are no scroll bars. Is this intentional?
• I just happened to have a Wakaba vericode image on my desktop, and when Xee opens it, the transparent background is noisy. Other transparent GIFs seem to be okay. Haven't tried an animated GIF yet...
• When more images are added to the folder Xee is currently browsing, Xee doesn't seem to become aware of them. Maybe the program could do a re-scan of the folder whenever it is brought to the background from the foreground?
• Trying to open another viewer while one viewer is open = hang. But I tried it a couple of other times and couldn't reproduce it...
• "Error loading image" on the attached image.
• The "fit to screen" isn't as pretty as Apple's. Also, will you be making a "full screen" mode that does away with the menu bar and status bar?

Not a bad little hack for a Mac n00b. Good work. :) Any significance to the name "Xee?"