Legend of the Green Dragon (LoGD) is a free, browser based homage to, and extension of, the original. Eric Stevens has done an excellent job preserving Able's style while adding tons of new features, characters and monsters, as well as vastly enlarging the world to include multiple cities and an afterlife. LoGD is written in PHP and is highly extensible. Different servers can offer very different experiences, so this review refers only to the classic server. A large list of others is available here.