I have worked closely with Paul for many years. His accomplishments are impressive. Under his leadership, IBM Research developed the Deep Blue supercomputer, which in May of 1997 defeated chess grandmaster Garry Kasparov in a six day match. A few years later, the Blue Gene initiative was launched, a family of highly parallel supercomputers aimed at solving some of the most complex problems in science and industry. Since 2004 Blue Gene has been number one in the Top500 list of the most powerful supercomputers in the world.
In technology, the Research division pioneered a number of semiconductor breakthroughs, such as the use of copper wiring to help build faster microprocessors and the use of self assembly, - inspired by biological mechanisms, - in semiconductor manufacturing.
Beyond individual products and technologies, Paul led in the creation of entire new disciplines, most famously Services Sciences, which is aimed at helping us better understand the nature of services, - by far the largest sector in the economy of most countries, - in order to improve their productivity and quality through the use of technology, science and management principles.
Paul played a major role in the launch of the Autonomic Computing initiative, aimed at making complex IT systems increasingly self-managing. In 2001 he published the Autonomic Computing Manifesto, a challenge to the IT industry, and the research community in particular, to deal with the growing complexity of IT systems - the largest obstacle standing in the way of continuing progress.
But, impressive as these accomplishments are, I believe that the key legacy from Paul Horn's tenure as director of IBM Research is his leadership role in transforming the very culture of the institution, and in the process laying the foundation for the corporate R&D lab of the 21st century.