Wikipedia: General Notions
First of all, it is
- a radical idea;
- founded by non-profit organization;
- everybody has a free access to Wikipedia;
- more than 1 mln articles in many languages;
- volunteers help a lot) ;
- volunteer system administration;
- 1.6 billion pages monthly;
- social concept of cooperation;
- neutrality policy which is not negotiable;
- you can also get RSS-support here;
- working methods are open;
- flexible methodology.