This volume contains the papers accepted for the 4th Workshop on Algorithm Engineering (WAE 2000) held in Saarbruc ] ken, Germany, during 5-8 September 2000, together with the abstract of the invited lecture given by Karsten Weihe. The Workshop on Algorithm Engineering covers research on all aspects of the subject. The goal is to present recent research results and to identify and explore directions for future research. Previous meetings were held in Venice (1997), Saarbruc ] ken (1998), and London (1999). Papers were solicited describing original research in all aspects of algorithm...

"E?ziente Algorithmen" was the title of the ?rst book by Kurt Mehlhorn in 1977. It was meant as a text for graduate students and published in German by Teubner-Verlag. We decided to adopt this title 32 years later for this Festschrift in honor of Kurt on the occasion of his 60th birthday. It contains contributions by his former PhD students, many of whom are now university teachers themselves, and colleagues with whom he cooperated closely within his career. It is our pleasure that even Kurt's former PhD advisor, Bob Constable from Cornell University,...