BYOND (Build Your Own Net Dream) is a suite of programs for creating and playing online games. Started in 1997 by a company named Dantom (which consisted of two people - Dan and Tom), it was initially called DUNG (Dantom's Universal Network Game). After a few years they rechristened it BYOND, reasoning that it's hard to sell something named DUNG.
BYOND is a powerful tool for creating online games with little time or budget, because it provides a pre-built network structure, a GUI, and sophisticted high-level programming tools. Although geared to RPG style gameplay, it is highly extensible and has been proven to work well with card games, board games, and even computer utilities that aren't games at all. Graphical (tile-based), rogue-like, browser-based CGI games, and pure text-based games are all possible. Registration on the website is free, and it provides access to a user forum, a unique "Key" commonly used for identification of gamers, and other services. The BYOND community is large and willing to help new users.
The BYOND suite of software that allows you to play, create, and publish BYOND games is free. A paid BYOND Membership includes benefits such as the BYOND Pager (an Instant_Messenger tied to the BYOND Key system), file storage space, subscription to the partner e-zine BYONDscape, a personal blog, and the ability to influence the rank of their favorite games in the network-wide BYOND Top-Ranked Games list.
Running the BYOND software, you will be asked if you wish to create a key. This key is usable for all BYOND games and the BYOND forums, and provides security from impersonators. Those who do not wish to create a key are welcome to use the universal "Guest" key, but that key is often banned from games because of the difficulty presented by moderation of guest users. Luckily, creating a key is free of charge and does not generate any spam or advertisments.
BYOND.com hosts a "Live! Hub" which lists BYOND games currently being hosted. The hub provides links to files that can be used to download and host games, as well as links to games that are already online.
Further detailed information about the DM language can be found in the DM reference.
DMCGI is especially powerful because it can easily interact with live BYOND worlds. The ease with which developers can export data such as frags, server uptime, and game statistics is one of the most attractive aspects of DMCGI. DMCGI can also make use of the BYOND Key system with its built-in authentication system. The developer is given the choice between classic methods of authentication or BYOND's own secure method, cutting yet more time out of development. All that users have to do is provide their BYOND key and password to Dantom's secure server and they are securely logged in.
BYOND user Zilal has made several tutorials that explain the basics of DM very well. Her first tutorial can be found at zilal.byond.com. Other tutorials can be found at BYONDscape's tutorials listing.
You can also ask for help on the developer forums.