See User-friendliness.
User Friendly is also the name of an online, daily comic strip about a small, Linux-based ISP. See http://www.userfriendly.org/static/ Also available in Dead Tree format:
- User Friendly by Illiad ISBN 1565926730
- Evil Geniuses in a Nutshell by Illiad ISBN 156592861
- The Root of All Evil by Illiad ISBN 0596001932
- Even Grues Get Full by Illiad ISBN 0-596-00566-0