Quantum Link

Quantum Link (or Q-Link) was a U.S. and Canadian online service for the Commodore 64 and 128 personal computers that operated starting November 5, 1985. It was operated by of Vienna, Virginia, which later became America Online. 
In October 1989 the service was renamed to "America Online" and the service was made available to users of PC systems in addition to Commodore users. The original Q-link service was terminated November 1, 1995 in favor of the "America Online" brand. 
The original Q-Link was a modified version of the PlayNET system, which Control Video Corporation licensed. Q-Link featured electronic mail, online chat (in its People Connection department), public domain file sharing libraries, online news, and instant messaging (using "On Line Messages", or "OLM"s). Other noteworthy features included online multiplayer games like checkers, chess, backgammon, hangman and a clone of the television game show "Wheel Of Fortune" called 'Puzzler'; and an interactive graphic resort island called Habitat while in beta-testing and later renamed to Club Caribe.
In October 1986 QuantumLink expanded their services to include casino games such as bingo, slot machines, blackjack and poker in RabbitJack's Casino and RockLink, a section about rock music. The software archives were also organized into hierarchical folders and were expanded at this time.
In November 1986 the service began offering to digitize users' photos to be included in their profiles, and also started an online auction service.
Connections to Q-Link were typically made by dial-up modems with speeds ranging from 300 to 2400 baud, with 1200 baud being the most common. The service was normally open weekday evenings and all day on weekends. Pricing was $9.95 per month, with additional fees of six cents per minute (later raised to eight) for so-called "plus" areas, which included most of the aforementioned services. Users were given one free hour of "plus" usage per month. Hosts of forums and trivia games could also earn additional free plus time.
Q-Link competed with other online services like CompuServe and The Source, as well as bulletin board systems (single or multiuser), including gaming systems such as "Scepter of Goth" and "Swords of Chaos". Quantum Link's graphic display was better than many competing systems because they used specialized client software with a nonstandard protocol. However, this specialized software and nonstandard protocol also limited their market, because only the Commodore 64 and 128 could run the software necessary to access Quantum Link.
In the summer of 2005 Commodore hobbyists reverse engineered the service, allowing them to create a Q-Link protocol compatible clone called Quantum Link Reloaded which runs via the Internet as opposed to telephone lines. Using the original Q-Link software as a D-64 file, it can be accessed using either the VICE Commodore 64 emulator (available on multiple platforms, including Windows and Linux), or by using authentic Commodore hardware connected to the Internet by way of a serial cable connected to a PC with internet access.
Club Caribe / Habitat.
One of the most influential Quantum Link games was "Club Caribe". Club Caribe was a predecessor to today's MMOGs.
Club Caribe was developed with Lucasfilm Games using software that later formed the basis of Lucasfilm's Maniac Mansion story system ("SCUMM"). Users controlled on-screen avatars that could chat with other users, carry and use objects and money (called "tokens"), and travel around the island one screen at a time. Club Caribe allowed users to take the heads off their character, carry it around or even set it down. However, other users could pick up heads that were placed on the ground, resulting in headless players exploring the game world. 
In February 2017, an open-source project to revive Habitat led by Randy Farmer (one of Habitat's creators) named NeoHabitat was announced to the public. The project is currently requesting volunteer contributors to aide in developing code, region design, documentation, and provide other assistance. Utilizing Quantumlink Reloaded, a new Habitat server was created which support the ability for an avatar to log in, manipulate objects, chat and navigate between sample regions. 