Educational puzzles, brain teasers, mathematical recreations and word games. A resource for anagrams, cryptograms, alphametics, word puzzles, logic problems, doublets, tangrams, chess, and math quizzes.

Recreations for active minds including games, puzzles, math, words, images, books, software and web guide.

Custom engravings for firearms and knives. Scrimshaw is also available. Specializing in historic recreations of classic engraving styles.

Offers real-time advanced physics software to help speed up prototyping and other simulations. Includes libraries to calculate rigid-body dynamics, collision detection, spring recreations and multiple-node joints.

Features interesting facts about different numbers. Includes favorite related links.