No single company owns the web. Its rules are open specifications written in public, and a feature becomes real only when engines implement them compatibly. Knowing who owns which document tells you where to look up exact behavior.
| Body | Specifications you use | How it works |
|---|---|---|
| WHATWG | HTML, DOM, Fetch, URL, Streams | Living Standards on GitHub 29 , updated continuously |
| W3C | CSS, WCAG accessibility, WebAssembly, many Web APIs | Working Groups; Candidate Recommendation to Recommendation |
| TC39 (Ecma) | ECMAScript (ECMA-262), the JavaScript language | Proposals advance through Stages 0 to 4; yearly edition |
| IETF | HTTP, TLS, QUIC, URIs, WebSocket protocol | RFCs by rough consensus and running code |
| WebDX CG (W3C) | Baseline status, the web-features 939 dataset | Classifies support across the core browsers |
WHATWG's Steering Group is Apple, Google, Microsoft and Mozilla, so a change lands in HTML only when implementers agree. TC39 works the same way for JavaScript. A proposal moves through Stage 1 (problem accepted), 2 (solution chosen), 2.7 (spec text and tests written), 3 (recommended for implementation) and 4 (two compatible shipping implementations), and each June Ecma approves that year's edition. ECMAScript 2026, approved on June 30, 2026, added Math.sumPrecise, Iterator.concat, Error.isError and base64 and hex methods on Uint8Array (JavaScript).
Baseline: is it safe to use yet?
A spec tells you what a feature should do, not whether your visitors' browsers do it. Baseline, introduced at Google I/O in May 2023 and now defined by the W3C WebDX Community Group, answers that with one label, computed from browser compatibility data for the core browser set: Chrome 1 and Firefox 555 (desktop and Android), Edge, and Safari 10 (macOS and iOS).
You will see Baseline badges on MDN 102 pages and in VS Code 550 hover cards (version 1.100 and later), and your tools can target it directly. Browserslist, which Autoprefixer 22,226 , Babel 41,624 and many linters read, accepts the queries baseline widely available and baseline 2024; Vite 8 25,978 's default build target is 'baseline-widely-available', which it pins to Chrome 111, Edge 111, Firefox 114 and Safari 16.4.
Each year the engine makers also run Interop, a joint effort to fix the features developers report as most broken across browsers, scored against the shared web-platform-tests suite. Interop 2026 has 20 focus areas, including View Transitions, the Navigation API, scroll-driven animations and container style queries.