Simply put, SaaS can be defined as "software deployed as a hosted service and accessed over the Internet." 

Today, SaaS applications are expected to take advantage of the benefits of centralization through a single-instance, multi-tenant architecture, and to provide a feature-rich experience competitive with comparable on-premise applications. A typical SaaS application is offered either directly by the vendor or by an intermediary party called an aggregator, which bundles SaaS offerings from different vendors and offers them as part of a unified application platform.

In contrast to the one-time licensing model commonly used for on-premise software, SaaS application access is frequently sold using a subscription model, with customers paying an ongoing fee to use the application. Fee structures vary from application to application; some providers charge a flat rate for unlimited access to some or all of the application's features, while others charge varying rates that are based on usage.

On the technical side, the SaaS provider hosts the application and data centrally-deploying patches and upgrades to the application transparently, and delivering access to end users over the Internet through a browser or smart-client application. Many vendors provide application programming interfaces (API) that expose the applications data and functionality to developers for use in creating composite applications. A variety of security mechanisms can be used to keep sensitive data safe in transmission and storage. Applications providers might provide tools that allow customers to modify the data schema, workflow, and other aspects of the application's operation for their use. (Source)

The founder of the Wiki model describes them as, "The simplest online database that could possibly work."

Wiki is a piece of server software that allows users to freely create and edit Web page content using any Web browser. Wiki supports hyperlinks and has a simple text syntax for creating new pages and crosslinks between internal pages on the fly.

Wiki is unusual among group communication mechanisms in that it allows the organization of contributions to be edited in addition to the content itself.

A wiki is an easy way to coordinate and collaborate on selected aspects of your company.  Some examples might be a wiki page of product prices and descriptions.  Perhaps you could post a page of company policies or best practices.  You could set up the members of your sales team or HR to have access to these pages for updating and adding content.  Edits can be recorded, so you'll always know who made which change and when.  Access can easily be restricted by password or user name.

Wiki applications abound.  All you need is a web host and the ability to upload to their server, usually with an FTP program.  Some knowledge of a programming languages is needed to set up a few of these applications.

MediaWiki - the WikiEngine used by the WikiPedia project, the DisinfoPedia project, WikiQuote, WikiBooks, WikiTravel, UncycloPedia, and others, including all wikis on WikiCities. It is the wiki engine that hosts the most public wiki pages.

PhpWiki - can run on relational databases (MySql, PostgreSQL, etc), DBM files, or flat files. Features include a plugin architecture so you can add all kinds of functionality, full version history, a large set of default pages (which document PhpWiki), InterWiki support, support for several languages, themes, RSS, many administrative functions (dump all pages as HTML, as a zip file, with metadata in mail-compliant headers, page locking, page deletion, and many more).

UseModWiki - an implementation of the original Wiki concept created by WardCunningham (standard Perl cgi-bin app with flat-file data storage and little configuration requried).
(Top Ten Wiki Engines)

Online office suites are becoming more prolific and more capable.  It's no wonder online suites are appealing: They offer the ability to have documents stored online and available anywhere you can access the Internet, no matter what operating system you're using. There's no software to download and install, no upgrading hassles when new features are added or bugs eliminated, and no upfront or ongoing expenses. The ability to share a document with several users without your own server is equally tempting, as is the price tag for many of these services: absolutely free.  Online applications can be a mixed blessing, however. If any server is stressed, you can't necessarily access the application when you need it.

If you or your company has a Gmail account through Google, you're probably already familiar with Google Docs.  Google Docs offers a word processor and a spreadsheet aplication, similar to Word and Excel.  In both apps, inviting others to edit or view your work is straightforward and easy. Both modules are very responsive; with the exception of File Open and File Save commands, there's little evidence you're working live online.  Google Docs accepts most of the popular file formats, including doc, xls, rtf and csv. 

Google Docs' formatting chops are sufficient for any business correspondence, such as letters or invoices. High-end documents don't render properly because Docs isn't 100% Word-compatible, nor does it claim to be.

For simple list-keeping and number-crunching, such as to perform a quick trial run of a budget or to do some fancy calculations on a limited set of data, Google Spreadsheets easily fits the bill. It's quick to launch, and if you know Word or Excel, you should have no problem understanding what to do. Spreadsheets has a few compatibility issues with Excel (array formulas aren't supported, for example), and its lack of charting support is a disappointment, but the application is fine for managing lists or creating ad hoc worksheets in a hurry (you know -- the kind when your boss asks a what-if question and needs the answer in 10 minutes).

Zoho's suite is a spry little collection of modules, taking only two seconds to launch the word processor (Writer) and spreadsheet (Sheet). The suite is extensive: it includes Projects (project management software), Show (presentations), Virtual Office (groupware with a calendar, e-mail client and more), Creator (database manager) and Planner (an organizer for reminders and notes).

Everything is by default stored in your 1GB online library, provided without charge. You can export in Word, PDF, RTF, text, HTML, SXW (StarOffice), ODT (OpenOffice), .sxw (StarOffice) and ODT (OpenOffice) formats.


ThinkFree has three main components -- Write (a word processor), Calc (a spreadsheet), and Show (presentation software) -- all of which are listed on the site's My Office page, along with your most recently edited files. If you're concerned about document compatibility with Microsoft Office, you want ThinkFree. There's simply no contest.

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. Though it lacks support for wild cards, the find feature can highlight all occurrences of your search term. You can add bookmarks, create table of contents entries, choose styles for your numbered lists, insert page breaks and use fields (including formulas).

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 PDFs. 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.

For the full reviews of these suites, visit ComputerWorld online.