Richard X

Richard Philips, best known by his stage name Richard X, is a British songwriter and music producer. Gaining attention as a pioneer of the bootleg craze, Richard X has earned success as a producer and remixer. He has helmed hit singles for artists including Annie, Kelis, Liberty X, Rachel Stevens and Sugababes. According to an early issue of the now defunct Popworld magazine, Philips' alias comes from a postcard which was sealed with a kiss misinterpreted for the letter X.

source: Wikipedia