|Can we use ruby for commercial |application? Yes. |Do we need to distribte our application with sources? No. If you're using regex.c comes with 1.8.2, you have to allow re-linking the binary (via supplying object files or dynamic linking), because it's LGPL. If you are using Oniguruma new regex engine, you have no such restriction. Gabriele Renzi added: IIRC 1.9 in the cvs already has oniguruma as the standard regex lib.