XLIFE -- a cellular-automaton laboratory This program will evolve patterns for John Horton Conway's game of Life. It will also handle general cellular automata with the orthogonal neighborhood and up to 8 states (it's possible to recompile for more states, but very expensive in memory). Transition rules and sample patterns are provided for the 8-state automaton of E. F. Codd, the Wireworld automaton, and a whole class of `Prisoner's Dilemma' games. See the file INSTALL for installation instructions. To use it, run `xlife'. The help key is `?'. There is a man page. The subdirectory `life' contains an extensive library of interesting Life patterns. The subdirectory `codd' contains transition rules and components for the universal computer-constructor described in E.F Codd's "Cellular Automata" Academic Press 1968 (ACM Monograph #3). The subdirectory `wireworld' contains patterns for the `Wireworld' automaton described in the January 1990 issue of Scientific American (Computer Recreations, p. 146). Some documents on advanced pattern creation and UCC components are in the directory doc. We also include a couple of utilities: The `lifesearch' program by David I. Bell has been included. You can use this to try to find interesting patterns and trace ancestry chains. There is a man page. The `lifeconv' utility converts between different pattern file formats. There is a man page. The `collect' utility collects separate included files into one file that uses pattern blocks. No man page, sigh. If you discover new and interesting life patterns, let us know! Please send the xlife savefile to esr@snark.thyrsus.com (the old address, jb7m+xlife@andrew.cmu.edu, is no longer valid). Or post to comp.theory.cell-automata These will be incorporated into the xlife distribution. Periodically, we will post the latest and greatest discoveries to comp.theory.cell-automata. Jon Dan Chuck Eric