Exactly how old is the World Wide Web?

It depends on what you define as the World Wide Web (i.e. how wide was
first considered "world wide", how many points are defined as a "web",
and if you are talking about the concept or the environment as we know
it today, etc).

The concept dates back to 1945.

The capability dates back to the 1960's.

Today's version came about in it's infancy in the late 1970's and early 1980's.

http://www.w3.org/History.html

regards;
tutuzdad-ga