Info

From Grokdoc

Info is a console program that displays the documentation for a program, if it is available on your computer. To use it type "info mycommand" at the prompt and hit the enter or return key (replace "mycommand" with the program you want information on.

If the info program starts up and displays something like "This is the top of the INFO tree" on the first line, the program you were looking for doesn't have any info documentation: type "q" to quit info and try man instead.