There are many resources on the Net that cover this topic, and instead of providing many of the products that I have listed here I will give you links to them.
Adventure games, also known more formally as Interactive Fiction, usually consist of a terminal or teletype not unlike to one that I am currently using now connected to a server which provides it with raw text, which usually describes what the player sees. The terminal user then enters a pseudoenglish or english phrase, which is said to describe wha they want to do next (such as "OPEN DOOR", "DRINK POTION", or in some extra- complicated cases phrases not entirely unlike "Please walk 15 meters west, the stop and pick up the rusty beer can, first throwing the javelin at the evil dragon.", but not quite as often as the first two). I hear that Activision was providing the ENTIRE collection of Infocom games on CD-ROM for the incredible price of $20us. This unprecidented offer has probably forever thrown the entire Interactive Fiction market off balance.
This site is a good source for interactive fiction games and compilers that you can use on many different kinds of computers.