Phil Bradley hat mit Pearltree 200 Suchmaschinen in Kategorien eingeteilt (via Stephen’s Lighthouse, Phil Bradley’s Website):
«This is a collection of over 200 different search engines in a variety of different subject areas – crucial search engines that you must know about, meta, multi, directory search engines, search engines that you can use to find out about social media material, video, sound, images and so on. If it doesn’t fit fully onto the screen for you, either click and drag it around, or use the zoom options in the bottom left hand corner.»