TLA

Three Letter Acronym.

TLA is the most popular type of acronym in computing terminology.

There are 26³ = 17576 possible acronyms, and probably most of them are already used. If we allowed numbers, special characters, or were case-sensitive, many more TLAs could be created.

Many TLAs have more than one meaning. There even are TLAs with more than 10 meanings (for example: SDI has at least 11 meanings). Many acronyms have more than one full-form with the same meaning. For example GCC was first 'GNU C Compiler', and later 'GNU Compiler Collection'.

Because on DOS only 3-letter file extensions (on DOS extension usually marked file type) were allowed, many longer acronyms were shorten to 3-letters (for example JPEG to JPG, HTML to HTM).

One big source of acronyms are short forms of Usenet groups. For example pra for pl.rec.anime.

Popular TLAs:

corporations: IBM, DEC
file types: PNG, GIF
hardware: CPU, FPU, RAM, ROM
licences: GPL, MPL
operating systems: GNU, BSD, DOS
other standards: UTC
programming languages: SQL
protocols: FTP, IRC
software: GCC, Gtk
time zones: GMT, UTC