Email Standards Project : The Email Standards Project is about working with email client developers and the design community to improve web standards support and accessibility ...
&what: Discover Unicode & HTML Character Entities : amp-what is a quick, interactive reference of 14,500 HTML character entities* and common Unicode characters, 8859-1 characters, quotation marks, punct...
AlsacréationS : Alsacréations est une communauté dédiée à l'apprentissage des standards web (W3C, HTML, XHTML, CSS) ainsi qu'à l'accessibilité numérique
The Big List of Naughty Strings : The Big List of Naughty Strings is a list of strings which have a high probability of causing issues when used as user-input data.
This site provides a collection of schemas that webmasters can use to markup HTML pages in ways recognized by major search providers, and that can also be used for structured data interoperability (e.g. in JSON).
Streeme : Streeme can serve music to most HTML5 compliant browsers and smartphone handsets using the computer you already own.
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
WebPlatform.org : Web Platform Docs is a community-driven site that aims to become a comprehensive and authoritative source for web developer documentation.