Bill Joy is Principal and Chief Scientist at Water Street Capital. Prior to this, he was an investor in Green practice at KPCB specializing in disruptive early-stage technologies in Wind, Solar PV, Energy Storage and Energy Efficient semiconductor and mobile technologies for especially mobile devices. He was also co-founder of Sun Microsystems and before that the main creator of Berkeley version of UNIX operating systems and applications for that system such as the vi text editor. He has issued more than 40 patents.