2d-rewriter is a cellular automata simulator. Key features: - Declarative input language for rules and initial patterns definition. - Ability to emulate Conway's "Life Game" via proper rules specification. - Ability to demonstrate self replicating loops. - Patterns are tried in 4 orientations. - Cell directions are defined against the pattern orientation. - Total number of rules can be substantially decreased by using sets and defining patterns using variables. - Required run time environment is a minimal X window system installation on a POSIX-compatible system (*BSD/Linux/Mac OS X/Cygwin/...).