It is a great pleasure to present this collection of papers from LCR ’98, the Fourth Workshop on Languages, Compilers, and Run-time Systems for Scalable Computers. The LCR workshop is a bi-annual gathering of computer scientists who develop software systems for parallel and distributed computers. LCR is held in alternating years with the ACM Symposium on Principles and Practice of Parallel Programming (PPoPP) and draws from the same community. This fourth meeting was held in cooperation with ACM SIGPLAN on the c- pus of Carnegie Mellon University, May 28{30, 1998. There were 60 registered attendees from 9 nations. A total of 47 6-page extended abstracts were s- mitted. There were a total of 134 reviews for an average of 2.85 reviews per submission. Submissions were rank ordered by average review score. The top 23 submissions were selected as full papers and the next 9 as short papers. The program committee consisted of David Bakken (BBN), Ian Foster (- gonne), Thomas Gross (CMU and ETH Zurich), Charles Koelbel (Rice), Piyush Mehrotra (ICASE), David O’Hallaron, Chair (CMU), Joel Saltz (Maryland), - spal Subhlok (CMU), Boleslaw Szymanski (RPI), Katherine Yelick (Berkeley), and Hans Zima (Vienna).