Regular research papers must not exceed 10 pages in ACM Proceedings style. Tool demonstration papers must not exceed 4 pages in ACM Proceedings style, and authors will be expected to present a live demonstration of the described tool at the workshop. Suggested topics, evaluation criteria, and writing guidelines for both research tool demonstration papers will be made available on the PEPM'08 web site. Papers should be submitted electronically via the workshop web site. The workshop proceedings will be published in the ACM Digital Library and selected papers will be invited for a journal special issue dedicated to PEPM'08.