CompuServe in the context of Terminal emulation

The Graphics Interchange Format (GIF; /ɡɪf/ GHIF or /dʒɪf/ JIF, see § Pronunciation) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on June 15, 1987.

The format can contain up to 8 bits per pixel, allowing a single image to reference its own palette of up to 256 different colors chosen from the 24-bit RGB color space. It can also represent multiple images in a file, which can be used for animations, and allows a separate palette of up to 256 colors for each frame. These palette limitations make GIF less suitable for reproducing color photographs and other images with color gradients but well-suited for simpler images such as graphics or logos with solid areas of color.

Tymshare, Inc was a time-sharing service and third-party hardware maintenance company. Competing with companies such as CompuServe, Service Bureau Corporation and National CSS. Tymshare developed and acquired various technologies, such as data networking, electronic data interchange (EDI), credit card and payment processing, and database technology. It was headquartered in Cupertino in California, from 1964 to 1984.

In 1984, Tymshare was acquired by McDonnell Douglas, to which Tymshare had sold its hospital accounting service in 1982. Tymshare was restructured, split up and portions were resold, spun off, and merged with other companies from 1984 through 2004 when most of its legacy network was eventually shut down. Islands of its network technology continued as part of EDI, into 2008.

Stephen Earl Wilhite (March 3, 1948 – March 14, 2022) was an American computer scientist who worked at CompuServe and was the engineering lead on the team that created the GIF image file format in 1987. GIF went on to become the de facto standard for 8-bit color images on the Internet until PNG (1996) became a widely supported alternative. The format later became the subject of a patent assertion by Unisys on its use of the LZW compression algorithm. Known as the inventor or creator of the GIF, Wilhite received a Webby Lifetime Achievement Award in 2013.

A bulletin board system (BBS), also called a computer bulletin board service (CBBS), is a computer server running software that allows users to connect to the system using a terminal program. Once logged in, the user performs functions such as uploading and downloading software and data, reading news and bulletins, and exchanging messages with other users through public message boards and sometimes via direct chatting. In the early 1980s, message networks such as FidoNet were developed to provide services such as NetMail, which is similar to internet-based email.

Many BBSes also offered online games in which users could compete with each other. BBSes with multiple phone lines often provided chat rooms, allowing users to interact with each other. Bulletin board systems were in many ways a precursor to the modern form of the World Wide Web, social networks, and other aspects of the Internet. Low-cost, high-performance asynchronous modems drove the use of online services and BBSes through the early 1990s. InfoWorld estimated that there were 60,000 BBSes serving 17 million users in the United States alone in 1994, a collective market much larger than major online services such as CompuServe.

AOL (formerly a company known as AOL Inc. and originally known as America Online) is an American web portal and online service provider based in New York City, and a brand marketed by Yahoo! Inc.

The service traces its history to an online service known as PlayNET. PlayNET licensed its software to Quantum Link (Q-Link), which went online in November 1985. A new IBM PC client was launched in 1988, and eventually renamed as America Online (abbreviated as AOL) in 1989. AOL grew to become the largest online service, displacing established players like CompuServe and Prodigy. By 1995, AOL had about three million active users.

A special interest group (SIG) is a community within a larger organization with a shared interest in advancing a specific area of knowledge, learning or technology where members cooperate to effect or to produce solutions within their particular field, and may communicate, meet, and organize conferences. The term was used in 1961 by the Association for Computing Machinery (ACM), an academic and professional computer society. SIG was later popularized on CompuServe, an early online service provider, where SIGs were a section of the service devoted to particular interests.

Talkomatic is an online chat system that enables real-time text communication among small groups. Each participant occupies a dedicated section of the screen, with messages appearing character-by-character as they are typed. Developed in 1973 by Doug Brown and David R. Woolley on the PLATO system at the University of Illinois, Talkomatic is recognized as one of the first multi-user chat systems, predating Internet Relay Chat (IRC) by 15 years and CompuServe's CB Simulator by seven years.

The system played a significant role in the development of online communities and influenced subsequent collaborative software, including Lotus Notes. After the original PLATO implementation was discontinued in the mid-1980s, Brown and Woolley released a web-based version in 2014. Following a temporary shutdown in 2024, the system was revived as an open-source project.

The Source (Source Telecomputing Corporation) was an early online service, one of the first such services to be oriented toward and available to the general public. The Source described itself as follows:

The Source was in operation from 1978 to 1989, when it was purchased by rival CompuServe and discontinued sometime thereafter. The Source's headquarters were located at 1616 Anderson Road, McLean, Virginia, 22102.