File Types

A document preparation system and markup language for high-quality typesetting. Standard in academia for scientific papers, theses, and mathematical documents.

A CSS preprocessor that extends CSS with variables, mixins, functions, and nesting. Less can run on the server (Node.js) or client-side in the browser.

A fast key-value storage engine by Google using LSM trees. Used internally by Chrome, Bitcoin Core, and as a backend for many databases.

The native file formats of LightWave 3D. .lwo stores 3D object data; .lws stores scene layout and animation. Historically used in TV production (Babylon 5, Battlestar Galactica).

A template language created by Shopify, written in Ruby. Liquid powers Shopify themes, Jekyll static sites, and other platforms, featuring safe sandboxed execution for user-facing templates.

Source code for Lisp (List Processing), the second-oldest high-level language (1958). Pioneer of many CS concepts including tree data structures, garbage collection, and dynamic typing.

A JSON-based animation format by Airbnb for rendering After Effects animations natively on web and mobile. Much smaller than GIF/video alternatives.

Media Playlist File: a plain text format for multimedia playlists containing file paths or URLs. Used by most media players and IPTV services.

MPEG-4 Audio: an audio-only MPEG-4 container commonly used for AAC-encoded audio. It is the standard format for music purchased from the iTunes Store.

MPEG-4 Video: a video container format developed by Apple, very similar to MP4. It is used primarily for video content in the Apple ecosystem and iTunes Store.

MATLAB data file for storing workspace variables, arrays, and structures. Widely used in engineering and scientific computing.

A generic term for a family of formats for storing collections of email messages in a single file, concatenated sequentially.

A specification for storing tilesets (map tiles) in SQLite databases. Used for offline map rendering and efficient tile serving.

Microsoft Access Database: the legacy database file format for Microsoft Access (prior to 2007).

Media Descriptor/Media Data File: a disc image format by Alcohol Soft where .mds contains metadata and .mdf contains the raw disc data.

MIME HTML: a web page archive format bundling HTML with all its resources (images, CSS, JS) into a single file using MIME encoding.

Musical Instrument Digital Interface: a technical standard for communication between electronic musical instruments and computers. MIDI files contain musical instructions, not audio recordings.

Medical Imaging NetCDF: a file format for medical imaging data developed at the Montreal Neurological Institute based on HDF5/NetCDF.

Matroska Video: an open, free container format that can hold unlimited video, audio, subtitle, and metadata tracks in a single file. Popular for high-quality video distribution.

Mobipocket e-book format: a digital book format originally for Mobipocket Reader and later adopted by Amazon Kindle. It has been largely replaced by KFX and EPUB.