GoogleDocs Online word processing documents, presentations and spreadsheets. Create and store online or upload existing documents and then edit collaboratively. See videos about GoogleDocs here, here, here, and here.
Google also has templates for documents, spreadsheets and presentations available for students and teachers
OpenOffice Downloadable open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It is available in many languages and works on all common computers. (Not an online tool, but popular and free.) See more here.
ZohoWriter Online word processor with collaborative features, templates. See also Zoho Sheet (spreadsheets), Zoho Show(presentations) Zoho Creator (databases), and more See a video about Zoho Writer here.
Zoho Notebook A central spot to collect information of all kinds and in many formats: text, web clippings, images, audio, webcams, video and more. Organize, edit, share and publish. See the video here.
Blist Online database tools.
Buzzword Online word processor from Adobe
gOffice ClassicOnline office suite
GreenDocWrite, save and publish documents without registration or an account.
Helipad Online document writing and sharing. Add tags. Access from anywhere. Automatic back-up.
MixedInk A "democratic" online collaborative writing tool. Gather opinions, vote for the best, combine into one document.
NumSum Online collaborative spreadsheets
PiratePad Collaborative writing and chat tool in one.
Shutterborg Online word processor. Easy to use.
Sync.in A web based word processor for real-time collaboration on a text document. You can see who is editing in real time and chat with them about the document. Each contributor's work is highlighted in a different color.
ThinkFree includes word processor, spreadsheet and presentation applications.
Versionate A collaborative word processor that remembers previous versions. Upload documents, edit with others, restore any version.
TypeWith.me Online collaborative text editing tool.
Writeboard Write, share, edit, revise, publish, compare versions and revert to any previous version.
WriteWith Upload documents, share with other people, chat, assign tasks, and track everybody's actions with a comprehensive history.
3D Writer Online writing with hypertext capabilities--choose your own ending, reports, projects.
A.nnotate.com lets you give, collect and store detailed notes on documents and web pages.
Celtx Free, downloadable storyboarding software. Share finished projects at the site.
LetterPop Online newsletter production and more (fees may apply)
MyBrochureMaker Make tri-fold brochures and flyers quickly with these colorful themes and templates
OpenZine Create your own magazine. Add images, video, articles...let others add content if you'd like. Select your own layout, etc.
Scribd "Web-based, document sharing community and self-publishing platform that enables anyone to easily publish, distribute, share, and discover documents of all kinds. E-books, presentations, essays, academic papers, newsletters, photo albums, school work, and sheet music are just a few of the different kinds of documents you can publish and share on Scribd."
PrimoPDF Converts Windows compatible documents into PDFs for free.
QuickTopic Document Review Upload and gather comments on any document.
WeBook Collaborative writinng and publishing. Start a book or story. Get feedback. Publish if you'd like!
Yudu It's a place where you can publish your expertise and creative work online, to promote, share or sell to the world.
50 Awesome Open Source Resources for Writers Word processors, reference sites, organizers, writing tools and web tools.