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

XML

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

Sitemap

A file in XML format that allows webmasters to inform search engines about URLs on a website that are available for web crawling.

Text

The plain text document format.

Sass

A stylesheet language that compiles to CSS and allows developers to use variables, nested rules, mixins, and functions.

IDN

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

Markdown

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

RDF

A W3C standard model to describe and exchange graph data on the web.

Prerender

The rel="prerender" attribute on HTML elements.

Humans.txt

A text file that can be created by developers to list the people who have contributed to a website.

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.

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.

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.

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.

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.

LLMs.txt

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

XMP

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

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.

Onion

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