[[Histologic]] is a constantly-updated, wiki-based comprehensive manual for the teaching of histology. It integrates still images from the [{{SERVER}}/library PEIR Digital Library] and whole slide images from the [http://peir-vm.path.uab.edu PEIR-VM] project. Still images are presented as thumbnails on the right margin of the text; clicking on these thumbnails will expand the images to full resolution. Whole slide images are presented in-line with the text, and can be manipulated using the mouse in much the same fashion as [http://maps.google.com/ Google Maps] or [http://maps.bing.com/ Bing Maps]; use the scroll wheel to change the magnification level, and drag to move the field of view. On the top left, there is a toolbar. Magnification level can also be adjusted using the + and - buttons on the toolbar. The rightmost button on the toolbar toggles fullscreen mode. On the top right corner of the whole slide image viewer, there is a thumbnail of the entire slide that the user may also use for navigational purposes. Finally, there is a navigational toolbox at the bottom of every page; from there, you can navigate to other chapters and chapter subheadings.