File Juicer and Mac OS X 10.5
File Juicer works on Mac OS 10.5 - this may be all you wanted to confirm.
"Leopard" presents few changes to File Juicer. JPEG files (and the 20+ formats File Juicer recognize) are still exactly the same and they are still found inside many file formats. The changes needed to support Leopard are mainly where files are found - the shortcuts in File Juicer's File Menu.
Safari's cache format has changed. Before Leopard, Safari used thousands of files to cache web browsing. Leopard use one large file instead. File Juicer can still search the file for images as on Tiger and Panther, although it takes a bit longer as it needs to do a full file search. This was not needed before.
Spotlight has been improved to let you search through your past Safari surfing - an excellent feature. It works by keeping a text file with the text on all the web pages you visit. The text files are located in your Library folder under Caches/Metadata/Safari and you can drop them on File Juicer to get to the text. It is however much simpler to use Spotlight or just double-click the file, so I have not added a shortcut in File Juicer.
Inside any FileIf you are curious about what there may be inside Leopard, you can drop parts of it onto File Juicer to see what it may contain. Here I have dropped Leopard's widgets onto File Juicer to see the images inside nicely presented in a very wide web pace Safari.