The Library Computer Access and Retrieval System (LCARS or simply library computer for short) was the name of the computer operating system employed  aboard Starfleet vessels, starbases and space stations in Star Trek. The term LCARS is mostly applied to the distinctive graphical user interface employed on the touch-sensitive panels of computer controls and consoles.  The unique designs of the LCARS displays are also known as Okudagrams - a reference to Michael Okuda, a technical adviser who created the definitive signage styles for a new design of control panel, without any physical controls, that was used in the later Star Trek movies and Star Trek: The Next Generation-era productions. This website uses an LCARS-themed user interface design.

The modern LCARS interface was first seen in the Star Trek: The Next Generation series in 1987. This was, in fact, the same year that the first version of Windows to use truly graphical user interfaces as found in LCARS. Windows 2.0. was released on November 1, 1987 - two months after Star Trek the Next Generation premiered) Windows 2.0 allowed for windows to overlap each other, in contrast to Windows 1.0, which could only display tiled windows. This version also introduced the window-manipulation terminology of "Minimize" and "Maximize" and a more sophisticated keyboard-shortcut mechanism. File management tasks were still managed by use of the MS-DOS Executive program, which was more list-driven than icon-oriented. The first Windows versions of Microsoft Word and Microsoft Excel ran on Windows 2.0.