In this paper, we first present a classification for existing GPS positioning algorithms based on their features of mathematical operations in the calculating process and the accuracy of the solutions solved. Then we systematically evaluate and compare the performance of GPS algorithms for practical environments. Performance metrics include normalized execution time and the absolute error. We examine the performance of traditional Newton-Raphson algorithm as well as those newly proposed ones. We find that while the traditional Newton-Raphson algorithm does deliver a reasonable performance, others may over-perform it by a good margin. © 2012 IEEE.