The programming languages zoo is a great resource for wanna-be interpreter/compiler writers. The ICFP 2000 programming contest is another great resource for wanna-be ray tracers. However until now there has been no OCaml resource for wanna-be Knowledge Representation tool-ers. This makes sound like KR tool is a more difficult area than other projects. ERic v0.3 demonstrates the opposite as it’s about 1200 lines size (lexer & hand-written parser included) and reads/writes a Conceptual Graph Interchange Format (CGIF) notation.
ERic v0.3 Zip archive
ERic v0.3 SVN repository