"Philips' improvement of 2009 just wasn't enough of an advance over the old stuff." Not so. Metaphone 3 is not a derivative work. Ralston's patent merely uses

"Philips' improvement of 2009 just wasn't enough of an advance over the old stuff." Not so. Metaphone 3 is not a derivative work. Ralston's patent merely uses (original 1990) metaphone as part of its design, and does nothing to improve it. The patent was abandoned because the U.S. Patent office informed me that it is no longer patenting algorithms.