This volume contains the proceedings of the International Symposium on C- puting in Object-Oriented Parallel Environments (ISCOPE 99), held in San Francisco, California, USA on December 8-10, 1999. ISCOPE is in its third 1 year, and continues to grow both in attendance and in the diversity of the s- jects covered. The original ISCOPE meetings and the predecessor conferences focused more narrowly on scienti?c computing in the high-performance arena. ISCOPE98 retainedthis emphasis, but broadenedto includediscrete-events- ulation, mobile computing, and web-based metacomputing. ISCOPE 99 cont- ues this trend. The ISCOPE 99 program committee received 41 submissions, and accepted 14(34%)asregularpapers, basedontheirexcellentcontent, maturityofdevel- ment, andlikelihoodforwidespreadinterest.Inaddition, theprogramcommittee selected six submissions as short papers. These papers were deemed to represent important workof a more specialized nature or to describe projects that are still in development. The 20 papers are divided into seven technical categories: Compilers and Optimization Techniques New Application Areas Components and Metacomputing Numerical Frameworks Generic Programming and Skeletons Application-Speci?c Frameworks Runtime Systems and Techniques This collection of 20 papers represents today's state of the art in applying object-orientedmethods toparallelcomputing.ISCOPE99istrulyinternational inscope, with its 52contributing authorsrepresenting21researchinstitutions in 8 countries. The ISCOPE 99 organizers are con?dent that the reader will share their excitement about this dynamic and important area of computer science and applications research. At the end of this volume, the author contacts section details the a?liations, postal addresses, and email addresses of all the proceedings authors.