The Third International Workshop on OpenMP, IWOMP 2007, was held at Beijing, China.This year'sworkshopcontinuedits traditionofbeingthe premier opportunity to learn more about OpenMP, to obtain practical experience and to interact with OpenMP users and developers. The workshop also served as a forum for presenting insights gained by practical experience, as well as research ideas and results related to OpenMP. A total of 28 submissions were received in response to a call for papers. Each submissionwasevaluatedbythreereviewersandadditionalreviewswerereceived for some papers. Based on the feedback received, 22 papers were accepted for inclusion in the proceedings. Of the 22 papers, 14 were accepted as full papers. We also accepted eight short papers, for each of which there was an opportunity to givea shortpresentationat the workshop, followed byposter demonstrations. Each paper was judged according to its originality, innovation, readability, and relevance to the expected audience. Due to the limited scope and time of the workshop and the high number of submissions received, only 50% of the total submissions were able to be included in the ?nal program. In addition to the contributed papers, the IWOMP 2007 program featured several keynote and banquet speakers: Trevor Mudge, Randy Brown, and Shah, Sanjiv. These speakers were selected due to their signi?cant contributions and reputation in the ?eld. A tutorial session and labs were also associated with IWOMP 2007.

This book constitutes the thoroughly refereed post-proceedings of the 18th International Workshop on Languages and Compilers for Parallel Computing, LCPC 2005, held in Hawthorne, NY, USA in October 2005.

The 26 revised full papers and 8 short papers presented were carefully selected during two rounds of reviewing and improvement. The papers are organized in topical sections on register optimization, compiling for FPGA's and network processors, model-driven and empirical optimization, parallel languages, speculative execution, run-time environments, high-productivity languages for HPC: compiler challenges, and compile-time analysis.