The 8th annual Petascale Tools Workshop (formerly the CSCADS Workshop on Petascale Tools) will be held August 4th-6th, followed by a half-day Dyninst/MRNet Users' Meeting on August 7th, this year in Madison, Wisconsin. Technical sessions will take place in the Computer Science building at 1210 W. Dayton St in Room 1240. As in previous years, we will begin with presentations of people's work, and will then break up into working groups to tackle real technical problems for the second half of the workshop.