Every UNIX command you ever dreamed of

I have a beautiful old artifact gathering dust on my bookshelf. The UNIX System User's Handbook, published by AT&T Bell Labs and Prentice Hall. At a terse 98 pages it listed all the commands you needed to know to get by back in those halcyon days.

These days, every flavor of UNIX has it's own unique and frustratingly different command set. AllCommands.com makes a good attempt to alleviate this problem and even includes a neat command search facility.