You can think of Writely as the Google version of Microsoft Word. You might ask, what's the big deal, Word is doing fine already. But let me tell you why I love Writely.
First of all, all your documents are saved online instead of being saved on your physical computer. This means if your computer breaks down, a hardware failure happens, your hard drive is locked or damaged or any other disaster happens to your computer, your documents will still be safe, having been saved online instead of being saved on your physical machine. Of course you access your online document via a username and password, so don't worry about any intruder gaining access to your private documents because they are secure. Another cool thing is that you might switch computers, in this case you can still easily access all your documents, because simply they are stored online. If you want to access your docs from home, from work or from anywhere, they are always there. Sure there is a catch to this, which is the computer must be connected to the Internet, but who hasn't got a net connection these days anyway. Hotspots are sprouting around, so even in the streets you'll have access to the net. The future is pointing towards total connectivity where you can access the net from just about anywhere.
Besides being able to access your documents from any computer, the second cool feature of Writely is that you can decide to share one or more of your documents with a friend or colleague. You may allow one of your friends to view a document you wrote. You may even give this friend permission not only to view your document but to edit it as well! Amazing! You are in control. You can allow as many people as you like to view or edit the documents you with them to view or edit. You will realize how cool this feature is when you actually use it. If you are working on a document of yours and one of your friends, whom you've granted permission to edit that document, is editing it at the same time, you almost instantly see the edits as your friend types them! Try it, because it is a lot of fun.