Developers like to write code for web applications with web based online tools. However such web-based code editors perform bit slow while comparing with desktop tools and applications. But nowadays such applications are focusing on providing a similar or better experience with desktop based ones.
1. BluePen Editor
BluePen Editor is a PHP-powered CSS editor that can be installed to any static or dynamic website and makes live CSS editing possible. Once triggered (with a bookmarklet), it opens the editor widget and makes all HTML elements hoverable so that blupePen can locate the CSS rules of them (like Chrome Dev Tools).
2. Dirty Markup
The editor used is the simple + functional AceEditor and there are multiple options for each beautifier to get the best results.
3. Rendra Online HTML5 Editor
Rendera is an online HTML5 editor which renders a realtime preview of your current work also transform your current work into CSS, Rendera supports HAML and SASS. Rendera makes learning HTML5 and CSS3 easy and it is built with CoffeeScript and Sinatra.
Maqetta is an open source project that provides WYSIWYG visual authoring of HTML5 user interfaces. The Maqetta application itself is authored in HTML, and therefore runs in the browser without requiring additional plugins or downloads. Maqetta is available under a commercial-friendly open source license. You can download the source code and install it on your own server, customize the code to fit your needs and/or contribute improvements to the open source project.
5. Amy Editor
6. JS Bin
CSSDesk is an Online CSS Sandbox. It allows people to quickly test snippets of CSS code, and watch the result appear live. I had very high ambitions for the project. There are line numbers and syntax highlighting appear live in the text box as you type. One of the greatest things is that it allows users to share their code with others as well.
RegExr is an online tool for editing and testing Regular Expressions (RegExp / RegEx). It provides a simple interface to enter RegEx expressions, and visualize matches in real-time editable source text. It also provides a handy RegExp snippet sidebar with descriptions and usage examples to make it easier to learn Regular Expressions through trial and error.
13. Shift Edit
DarkCopy is a simple, full-screen text editor for distraction free writing. DarkCopy is for anyone who enjoys the simplicity of a typewriter, and wants to increase productivity by focusing only on writing.
Dabblet is an interactive playground for quickly testing snippets of CSS and HTML code. It uses -prefix-free, so that you won’t have to add any prefixes in your CSS code. You can save your work in Github gists, embed it in other websites and share it with others.
18. JS Hint
20. Gist Box
Finally I am adding Gist Box which lets you easily organize code snippets. Your library is saved to the cloud for backup. Never worry about snippets getting lost in the shuffle. GistBox was built on standard HTML5 technologies. On the go or at the office, you’ll always have GistBox.