[WaveDrom] is Free and Open Source online digital timing diagram (waveform) rendering engine that uses javascript, HTML5 and SVG to convert [WaveJSON] input text description into SVG vector graphics.

[WaveJSON] is an application of the JSON (JavaScript Object Notation) format. The purpose of WaveJSON is to provide a compact exchange format for digital timing diagrams utilized by digital HW / IC engineers.

WaveDromEditor is online real-time editor of digital timing diagrams based on [WaveDrom] engine and [WaveJSON] format. The engine using [WaveDromSkin] skin mechanism to render complete picture. Multiple timing diagrams can be embedded into your HTML page as described in [WaveDromPlugins].

Explanation of the risks of using JavaScript in Web browsers and e-mail clients (in german).

JavaScript-based tool to draw diagrams using ASCII characters.

D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG and CSS. D3’s emphasis on web standards gives you the full capabilities of modern browsers without tying yourself to a proprietary framework, combining powerful visualization components and a data-driven approach to DOM manipulation.

Yet another emulator for the 6502 microprocessor. The site also has an interesting toy unix written in JavaScript.

Interesting way to authenticate and encrypt HTTP without using SSL. Note the security concerns in some of the comments.

Ymacs is an Emacs-like editor that works in your browser. Currently (starting with tag v0.4 in the code repository) it works in recent versions of Firefox (and other Gecko-based browsers), Google Chrome and Apple Safari.

TinyMCE is a platform independent web based JavaScript HTML WYSIWYG editor control released as Open Source under LGPL by Moxiecode Systems AB. It has the ability to convert HTML TEXTAREA fields or other HTML elements to editor instances.

Web calculator implemented in JavaScript. Implements arbitrary precision, plotting, prime testing, polynomial roots, matrix arithmetic and very limited (polynomials) symbolic integration. Written by Fabrice Bellard, who also wrote TinyCC, QEmacs, FFMPEG, QEMU and more.