Rated 5 out of 5 stars
Works flawlessly with almost any other addon or interface modification.
Only aroblem: The text in sidebars like bookmarks is a little hard to read due to the transparent background.
It would be nice if it was possible to give the text a white shadow or change the transparency settings for the sidebar, like with every other part of the window.
The bookmarks and history sidebar content doesn't allow much customization. Some changes (background color/transparency) would have a negative effect on some other Firefox settings and windows. It is also not possible for bookmark/history content to have text shadows. The only feature I can provide atm, is a font color selector for those text areas. Check the latest devbuild (Version 1.1pre4): https://addons.mozilla.org/addon/glassmyfox/versions/