Why there are a special syntax for links to Wikipedia (like \Def[graph]{graph theory}), but there are no special syntax for links to PlanetMath (http://planetmath.org). Sometimes is better an entry in one or the other of these two competing encyclopedias for mathematics. Please add s syntax for links to PlanetMath (just like as it exists for Wikipedia). Also change at http://garden.irmacs.sfu.ca/?q=purpose "frequently be found on Mathworld and Wikipedia" to "frequently be found on Mathworld, Wikipedia, and PlanetMath".