Wikipedia.org went online January 15 in 2001.
The idea was to create an encyclopedia that everyone could contribute to.
This idea has become one of the largest knowledge bases in the world.
The open format led to many people sharing knowledge.
However the attention also attracted misinformation and abuse. Which led to a more tighter policy on contributions enforced by a dedicated team that keeps our favorite encyclopedia a good source to find information on an ever expanding range of subjects.