What is a word for a person who loves to share knowledge? So far I have educator in mind. Is there any other word?
How about "maven"? According to the Wikipedia article,
A maven (also mavin) is a trusted expert in a particular field, who seeks to pass knowledge on to others.
[Admittedly, many dictionaries define the word merely as something like "an expert", but the meaning is in flux, and the "person who loves to share knowledge" meaning is getting more common.]
A pedagogue likes to teach others things.
How about "pundit"? A pundit is
a person who knows a lot about a particular subject and who often talks about it in public
Within religion and technology people who are keen to spread ideas are know as evangelists.
For evangelists who are promoting knowledge of a certain type of technology or religion, spreading the 'word' is seen as it's own reward, rather than seeking any monetary reward.
A fountainhead is a person who is a source of all kinds of knowledge. S/he may not love sharing that knowledge, however.
On the other hand, why would a fountainhead deliberately dam up the works by refusing to share knowledge? Besides, isn't the job of a literal fountainhead to benefit all the people who congregate around it? How could a fountainhead of knowledge not love benefitting others?
Yeah, fountainhead is an apt word to describe someone who loves sharing knowledge.