I am running this on windows 7. It is the only free (and opensource) software I have found which can handle XMP metadata with png files. This is something even photoshop cannot currently handle correctly relying on fireworks and bridge. Essentially this means I can tag all my images in png format and maintain metadata with the files so that if for example I upload any to flickr the tags, description and title are all maintained. Fantastic!

I have also found the software very intuitive and got used to it much quicker than Picasa which I have dumped in favour for this.

Definitely a great app. Unfortunately it's KDE not GNOME which for anyone who pays attention to that may be an eyesore, or at least an irritant. Other than that, to me it far outweighs similar FLOSS apps like RAWTherapee and certainly Darktable.