Overview and charge - Snowmass Workshop 2005

This contribution to the published Proceedings records the opening talk I presented on the first morning of the 2005 International Linear Collider Workshop in Snowmass, CO, August 14 - 27, 2005. It includes a summary of the motivation for the workshop, the scientific goals and charges for the working groups, the initial plans of the accelerator, detector, and physics groups, and the activities of the communication, education, and outreach group. This document also describes organizational aspects of the meeting, particularly the scientific committee structure, the self-organization of the working groups, the composition of the indispensable secretariat and computer support teams, and the sources of funding support. The report serves as an introduction to the proceedings whose individual papers and summary documents must be consulted for an appreciation of the accomplishments and progress made at Snowmass in 2005 toward the realization of an International Linear Collider