A backward-compatible CSS language extension inspired by Sass that supports variables, mixins, operations, and functions.

Text

The plain text document format.

RelMeAuth

A proposed open standard for using rel-me links to profiles on OAuth supporting services to authenticate via either those profiles or your own site.

Sitemap

A specialized XML file that lists a website's URLs and helps search engines discover pages available for crawling and indexing.

Markdown

A lightweight markup language used to add formatting to plain text documents using simple, human-readable syntax.

Humans.txt

A plain text file that allows website creators to identify and credit the people involved in developing a website.

XML

A markup language and file format for storing, transmitting, and reconstructing structured data in a platform-independent way.

OpenAPI

A specification language for defining HTTP APIs, typically written in YAML or JSON.

XRDS

An XML-based file format that provides a list of service endpoints (e.g., OpenID) available on a website.

Prerender

A deprecated browser hint that instructed web browsers to preload and render a web page in the background before navigation occurred.

LLMs.txt

A proposed standard that provides structured content and instructions to guide large language models in understanding and summarizing a website's content.

AdChoices

A self-regulatory standard for online interest-based advertising that gives consumers enhanced control over the collection and use of their data to deliver relevant ads.

WebAssembly

A portable binary instruction format that runs in modern web browsers with near-native performance, enabling frontend coding in languages that were not traditionally used for web interfaces, such as C/C++, C#, and Rust.

Rack

A minimal, modular interface and invocation convention that operates between Ruby web servers and web applications to standardize how HTTP requests and responses are exchanged.

JSON Web Token

An open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object.

Webmention

A simple protocol to notify any URL when a website links to it, and for web pages to request notifications when somebody links to them.

ActivityPub

A decentralized social networking protocol used by various Fediverse services such as Mastodon, Pixelfed, and PeerTube.

OpenTelemetry

An open-source, vendor-neutral observability framework and toolkit for collecting, processing, and exporting telemetry data such as traces, metrics, and logs.

WCAG

The Web Content Accessibility Guidelines are an international standard developed by the W3C that defines how to make web content, including text and media, accessible to people with disabilities.

Onion

Sites are websites on the dark web that use the .onion top-level domain and are only accessible through online routing through Tor.

XMP

An ISO standard for creating, processing, and exchanging metadata for digital documents.

IDN

Internationalized Domain Names allow people around the world to use domain names in local languages, such as Arabic, Chinese, or Cyrillic.

ESI

A simple markup language used to define web page components for dynamic assembly and delivery of web applications at the edge of the Internet.

A non-proprietary protocol for encrypting email using public key cryptography.

IndieAuth

A decentralized identity protocol built on top of OAuth 2.0.