Itisan honoranda pleasure topresentthiscollectionofpapersfromLCR2000,the?fth workshop on Languages, Compilers, and Run Time Systems for Scalable Computers, held in Rochester, N.Y., U.S.A., on May 25–27, 2000. The LCR workshop is a bi annual gathering of computer scientists who develop software systems for parallel and distributed computers, held in the off year for the ACM Symposium on the Principles and Practice of Parallel Programming (PPoPP). This ?fth meeting was held in cooperation with ACM SIGPLAN on the University ofRochester campus. A totalof38six pageabstracts were submitted,ofwhich22 were chosen for presentation and publication. Each paper received a minimum of 3 reviews, with 122 reviews in total. There were 44 registered attendees. Local arrangements were coordinatedbyKristenWondrack,alongwithSara Sadick and Mary Albee, from the University of Rochester conference and events of?ce, and JoMarie Carpenter from the University of Rochester department of computer science. Grigorios Magklis was the webmaster for the workshop. I would like to thank all of them for an excellent job, and in particular, Kristen Wondrack, for helping ensure an enjoyable workshop that also proceeded smoothly. I hope the participants were able to take advantage of some of the attractions in Upstate New York as well.