Phred was originally conceived in the early 1990s by Phil Green, then a professor at Washington University in St. Louis. LaDeana Hillier, Michael Wendl, David Ficenec, Tim Gleeson, Alan Blanchard, and Richard Mott also contributed to the codebase and algorithm. Green moved to University of Washington in the mid 1990s, after which development was primarily managed by himself and Brent Ewing. Phred played a notable role in the Human Genome Project, where large amounts of sequence data were processed by automated scripts. It was at the time the most widely used base-calling software program by both academic and commercial DNA sequencing laboratories because of its high base calling accuracy. Phred is distributed commercially by [http://www.codoncode.com CodonCode Corporation], and used to perform the "Call bases" function in the program CodonCode Aligner. It is also used by the MacVector plugin Assembler.