Brent has experience building software systems from the device driver level up through network servers, user applications, and graphical user interfaces. He has been using Tcl since it was first created by John Ousterhout. Some of his more interesting Tcl/Tk applications include the Exmh email user interface and the TclHttpd web server. He has written a book, Practical Programming in Tcl and Tk, that is now in its third edition. Brent received his PhD in Computer Science at Berkeley for his work on the Sprite distributed file system.