Universal Systems Language

It was designed by Margaret Hamilton based on her experiences writing flight software for the Apollo program.

[1] The language is implemented through the 001 Tool Suite software by Hamilton Technologies, Inc.[2] USL evolved from 001AXES which in turn evolved from AXES all of which are based on Hamilton's axioms of control.

USL was inspired by Hamilton's recognition of patterns or categories of errors occurring during Apollo software development.

[6] It is not only a formalism for software, but also defines ontologies for common elements of problem domains, such as physical space and event timing.

The process of developing a software system with USL together with its automation, the 001 Tool Suite (001), is as follows: define the system with USL, automatically analyze the definition with 001's analyzer to ensure that USL was used correctly, automatically generate much of the design and all of the implementation code with 001's generator.

Figure. 1 The three primitive control structures and their rules form a universal foundation for constructing maps in the domains of time and space as FMaps and TMaps