These articles provide how-to information to help you make use of specific technologies and APIs.

HTML Learning Area: HyperText Markup Language (HTML) is the core language of nearly all Web content. Most of what you see on screen in your browser is described, fundamentally, using HTML.
CSS Learning Area: Cascading Style Sheets (CSS) is a stylesheet language used to describe the presentation of a document written in HTML.
Events developer guide: Events refers both to a design pattern used for the asynchronous handling of various incidents which occur in the lifetime of a web page and to the naming, characterization, and use of a large number of incidents of different types.
Graphics on the Web: Modern Web sites and applications often need to present graphics of varying sophistication.
Guide to Web APIs: A list of all Web APIs and what they do.
JavaScript: JavaScript is the powerful scripting language used to create applications for the Web.
Localizations and character encodings: Browsers process text as Unicode internally. However, a way of representing characters in terms of bytes (character encoding) is used for transferring text over the network to the browser. The HTML specification recommends the use of the UTF-8 encoding (which can represent all of Unicode), and regardless of the encoding used requires Web content to declare that encoding.
Mobile Web Development: This page provides an overview of some of the main techniques needed to design web sites that work well on mobile devices. If you're looking for information on Mozilla's Firefox OS project, see the Firefox OS page. Or you might be interested in details about Firefox for Android.

Optimization and performance: When building modern Web apps and sites, it's important to make your content work quickly and efficiently. This lets it perform effectively for both powerful desktop systems and weaker handheld devices.
Parsing and serializing XML: The Web platform provides different methods of parsing and serializing XML, each with its own pros and cons.
The Web Open Font Format (WOFF): WOFF (Web Open Font Format) is a font file format that is free for anyone to use on the web.
Using FormData Objects: The FormData object lets you compile a set of key/value pairs to send using XMLHttpRequest. It's primarily intended for sending form data, but can be used independently from forms in order to transmit keyed data. The transmission is in the same format that the form's submit() method would use to send the data if the form's encoding type were set to "multipart/form-data".
Glossary: Defines numerous technical terms related to the Web and Internet.

See also