Vern Paxson wrote flex with the help of many ideas and much inspiration from Van Jacobson. Original version by Jef Poskanzer. The fast table representation is a partial implementation of a design done by Van Jacobson. The implementation was done by Kevin Gong and Vern Paxson. In 2001, W. L. Estes took over as maintainer of flex. John Millaway is a co-author of the current version of flex. He has contributed a large number of new features, fixed a large number of outstanding bugs and has made significant contributions to the flex documentation.