A Graphics Interchange Protocol and Format, including System Tools

Most research groups over a period of time develop and acquire enough different programs and devices that they are in a position to appreciate the advantages of some common means of communicating information between them. In a small dynamic research environment, however, fixing everyone to a single inflexible standard is usually unacceptable because changes in programs and devices occur at a rapid rate, quickly outdating the standard. We've attempted to resolve these two conflicting concerns by staging a flexible interchange format system into two distinct levels. The bottom level, the protocol level, is essentially the underlying language in which the format is written . The top level, thejormatlevel, is where the interchange format is actually expressed. The strength of this division is twofold: uniformity of syntax, allowing high-level parsing tools to be built; and flexibility of semantics, allowing a format which can evolve along with the user community in the least painful way. Detailed descriptions of the protocol, a typical format, and the system tools expected to be provided with an implementation of the protocol are presented.