DBook!

Google Docs is an online word processor, part of Google Drive , that lets you create and format text documents and collaborate with other people in real time. Here's what you can do with Google Docs:

AbiWord is a free software word processor. The name "AbiWord" (pronounced "Abby Word") is derived from the root of the Spanish word "abierto", meaning "open". It runs on Linux, Mac OS X (PowerPC), Microsoft Windows, ReactOS, BeOS (unsupported), AmigaOS 4.0 (through its Cygnix X11 engine), and other operating systems. Multilingual Portable version (15MB installed) from http://portableapps.com/apps/office/abiword_portable .

StackEdit is a free, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.

Office Online is an online office suite offered by Microsoft, which allows users an easy way to access, view, create and edit documents using lightweight, web browser-based versions of Microsoft Office applications:

MarkdownPad is a full-featured Markdown editor for Windows. Features: LivePreview : Instantly see how your documents look in HTML as you create them. Easy formatting with keyboard shortcuts. Markdown formatting can be applied (and removed) with handy keyboard shortcuts and toolbar buttons.

ghostwriter is a Windows and Linux text editor for Markdown, which is a plain text markup format created by John Gruber. ghostwriter provides a relaxing, distraction-free writing environment, whether your masterpiece be that next blog post, your school paper, or your NaNoWriMo novel. Here are just a few of its features:

Real-time collaborative text-editor. No account required. Edits highlighted in authors color. Infinite undo history. Copy of the down EtherPad.

An online word processor that lets you create and edit documents in your web browser and save them in the cloud, so that you can share them with anyone. Zoho can allow multiple users to work on a document simultaneously. Import Microsoft Word (DOC), OpenOffice text (ODT & SXW), HTML, RTF, JPG, GIF PNG files.

Store and edit documents in the cloud without sacrificing your privacy

Start writing notes, docs, and blogs quickly using Markdown.

Fidus Writer is an online collaborative LaTeX editor especially made for academics who need to use citations and/or formulas. The editor focuses on the content rather than the layout, so that with the same text, you can later on publish it in multiple ways: On a website, as a printed book, or as an ebook. In each case, you can choose from a number of layouts that are adequate for the medium of choice.