Now I know that many of you are wondering why I'm not listing MS free version that comes with your hotmail or live account. The reason is simple; cross comparability, it's not there. The free on line version does not give you the opportunity to save your documents as either an earlier version of office or in a different format. You can however download the document to your local drive and then convert it. (kind of counter intuitive for an on line office app)

Also not mentioned here are the number of Free office suites that are available for installation on your PC, such as Libre office to name just one. That in another article later.

1. Think Free Office - The #1 Choice

Think Free Office is one of the only Java-based on-line office suites. The upside to that is Think Free Office will make many users feel like they are using a more standard client-based app. Think Free also offers the Think Free Power Tool which enables you to automatically sync your Think Free Office with your PC and also has a Mobile Site to make it easy to interact with your Think Free Office from your mobile device.
If you're concerned about document compatibility with Microsoft Office, you want ThinkFree. There's simply no contest. ThinkFree's opening page shows your most recently used files. Right from the start, you know things are different. ThinkFree Write offers two modes of operation when you open a file and see a preview screen. 1. Quick Edit mode offers a minimal interface -- a few toolbar buttons for simple editing, reminding you more of WordPad than Word. 2. Power Edit which looks more like a full application: menus, a rich toolbar, a ruler bar and even a drawing toolbar similar to Word's for inserting elements such as AutoShapes, text boxes, clip art, and pictures. In fact, ThinkFree's Power Edit menu reveals a startling number of word processing features, from columns and drop caps to AutoCorrect and table manipulation, such as merging cells, distributing cells evenly across the page, repeating header rows.
ThinkFree Write allows you to insert images from clip art, from an image file, or directly from Flickr, a popular photo-sharing service. Right-click on a misspelled word (which is underlined with a red squiggly line) and ThinkFree Write offers properly spelled alternatives. There's undo and redo, zoom levels and the ability to save files as PDF's. You can also publish your documents to your own Web site using HTML that ThinkFree generates, attach ThinkFree or Microsoft Office documents to articles in your WordPress blog or other options.

Think Free Office Suite

 

2. Zoho

Zoho offers the standard office tools, it has a host of features and services that can be included. One of my favorite additions is the Campaigns tool. With this you can create email and social campaigns for up-coming services and products. If you are a small business owner, you would certainly stand to gain quite a lot of additional efficiency and functionality by migrating to Zoho. You can start a free account (which is ideal for single users), or you can upgrade different products, in an a la carte fashion, to perfectly fit your needs.

ZoHo Office Suite

3. OX

OX is the new kid on the block. Though it's not one hundred percent production ready, it's already showing incredible promise. OX offers files, email, address book, calendar, tasks, and even a social portal where you can easily keep up with your Facebook and Twitter accounts from within the OX Portal. OX is also one of the few fully open source tools of its kind, which should make many of the Google Docs opponents happy. Even though OX isn't quite ready for everyday use, you should sign up and check it out - make sure the developers are looking at plenty of interest and support. Once complete, OX will be able to seamlessly work with both Microsoft Office and LibreOffice files/formats.

OX Office Suite

4. Google App's

Breaking News May 14, 2014
Looks like the new Docs and Sheets apps were harbingers of changes for Google Drive. The good folks at Android Police parsed Drive's new, currently unreleased version and discovered that it no longer has document or sheet editing capabilities. Should you try to make changes, the app prompts you to download the appropriate app to do so. Choose not to download and attempt to open a file, and you'll be greeted by a view-only mode. While users may be a bit miffed at being force-fed a pair of new apps, it may prove beneficial. Separating the doc editing and cloud storage components will (presumably) let Google streamline the experience for each and give you option to download only the apps you need.  This does not however apply to the Internet desktop application version.  Only the mobile apps.

Google App's used to be the de facto standard by which everyone measured on-line office suites. With a lot of features, millions of users, and an incredibly simple to use interface, it's hard to go wrong with Google App's Word processing, spreadsheets, presentations, forms, drawings, tasks, and lucid art diagrams are all at your fingertips. And, of course, we cannot forget email. For the single user, Google Drive is suitable. If you are a business owner, give Google App's for Business a try. Five million businesses are already taking advantage of this powerhouse on-line suite of tools. Though there may be some comparability issues with MS Office users.

Google Docs

 

5. Live Documents - An up and coming favorite

Live Documents is driven by Flash and offers an interesting take for the on-line office interface. Instead of the standard menu or tab-driven applications, Live Documents presents itself as a full-blown virtual desktop. Along with the standard tools (word processor, spreadsheets, presentations) it also offers Google Docs imports, a quick-launch dock, and a host of formatting tools (from within each tool). You can adjust text kerning, add footnotes, share documents with other users, and more. Imported documents (from Google, Microsoft Office, or LibreOffice) do not lose formatting or data).

Live Documents Office Suite