[robin_reala]

Just HTML, not anything else.

[Macha]

Note however that HTTP is a IETF standard, Javascript is an ECMA standard, so of the core web components, CSS is the last they control.

[robin_reala]

Right, but that’s not the only thing they do that’s used on the web. They also own and run XML, security specs like CSP and SRI, the WCAG accessibility guidelines, Web Payments, WebAuth, WebRTC, etc etc.

They also do non-web stuff that happens to use web standards, for example ePub3.

[frivoal]

Depending on what you consider core: also SVG, WebRTC, ServiceWorkers, Aria, Web Payments, WOFF, Web Audio…