LCARS is an imaginary computer systems architecture, referred to in Star Trek television shows. Within Star Trek chronology, the term was 'first' used in The Next Generation, and in 'subsequent' shows. Below is an overview of LCARS, written within a Trek context.

The Library Computer Access and Retrieval System is the collective designation for a set of hardware configurations, software algorithms , and communication protocols that, collectively, define design standards for devices that form the computational backbone relied upon by Federation worlds.

Below is a brief overview of the three specification sets (also termed specsets) that make up LCARS:

Table of contents
1 Hardware
2 Software
3 Communication Protocols

Hardware

A number of circuitry configurations and component designs are specified for use in Federation computing devices. The diversity of designs included within the hard-spec reflects the wide variety of capacities and applications which the LCARS standard encompasses. Of the three spec-sets, hardware is the most loosely defined, due to continuing technological development, as well as the need to integrate existing systems on member worlds. Current technology revolves around isolinear optical chips, which can be enhanced in large-scale systems through the application of subspace fields.

Software

The LCARS soft-spec (LCARS/ss)is based on 114 subsets of reusable, interoperable code modules. Each subset is designed to handle most functions associated with computing applications. Within each subset are specialized variants, geared to specific applications. For example, with the Pattern subset are code modules designed to enhance vocalization in communicator audio; detect radiation anomalies in nebulous matter; and detect evasion patterns in combat situations. These modules are exhaustively spec-ed, enabling anyone from an engineer to a field-user to adapt them to unique uses.

Communication Protocols

This spec-set is perhaps the most diverse, as it must accommodate the communication needs of thousands of species, their languages, and their various modes of communication. A core element of the comm-spec is the Universal Translator, a tightly-recursive set of algorithms that can decode unknown forms of communication. Data sets generated by the UT are regularly introduced into the Comm spec-set, after review by Federation linguistics specialists.