When the computers become more and more common Encyclopedias is by their structure of words and cross references extremely well suited for moving the contents from the book format to the computer format. Firstly because it is a lot easier to carry around and find what you are looking for and secondly because it is possible to include sounds and films as illustrations.
[Wikipedia] -- [Nupedia] -- [Britannica] -- [Encarta] -- [Columbia Concise]