what is typo3, new to typo3

What is typo3??
(This post is for all who don't know what is typo3 and those who are new to typo3.)
Typo3 is a free(open source) CMS( Content Management System) developed by TYPO3.org. I am using lots of free open source CMS but this is the most powerful cms that I have seen ever. I am really enjoying learning and developing with Typo3. It is bit difficult to learn but once you learn this CMS you can develop websites more faster , which is a main advantage of this CMS.
Features of Typo3 CM
This CMS is very powerful and very fast to create static and/or dynamic websites. Lots of important features are provided in this CMS which makes our development faster. Following are some of the important features of typo3 CMS.
1. Faster development.
2. Easy Extensions.
3. User can develop there own extensions.
4. Great user(developer-editor) interface.

As I said earlier typo3 very fast while developing websites, let me explain one point with respect to its speed.
* Once you finished your template mapping and/or menus creation, you can create new pages in just 3-4 clicks.Can you imagine its speed.
* Page contents (say different paragraphs/images/graphic media) can be treated as saperate element and thus developer can edit/delete any piece of these paragraphs.
* Developer can easily Show/Hide these saperate elements in single click.
* Any of these contents can be copied from one page to other page. Isn't it great.
(go through other posts to learn other important features of typo3 cms)