jTans is a Java version of Tangram, an ancient Chinese puzzle. The object is to put 7 geometric shapes together to form a given outline. All of the pieces must be used and are laid next to one another. It can be run as a Java 2 applet, a standalone application, or a Web Start application.
libpuz is a C library implementing the .PUZ crossword file format. It allows users to read binary and text PUZ files and create binary PUZ files openable by Across Lite and other crossword programs. Also included is a (mostly) complete specification of the file format and checksum routines, in case you want to implement PUZ in a language other than C.