Peter Seibel is a serious developer of long standing. In the early days of the Web, he hacked Perl for Mother Jones and Organic Online . He participated in the Java revolution as an early employee at WebLogic which, after its acquisition by BEA, became the cornerstone of the latter's rapid growth in the J2EE sphere. He has also taught Java programming at UC Berkeley Extension. He is the author of Practical Common LISP from Apress.