The Sustainable Business 20 (SB20) highlights “20 public companies that are leading the way to a sustainable society,” according to Progressive Investor, which has produced this list for the past seven years.

SB20 companies must excel by both sustainability and financial criteria, and they include both established companies and smaller innovators, like Accsys Technologies – an English firm developing sustainable substitutes for precious hardwoods. Larger players include IBM, which aims to cut data center energy use by half by 2010, while increasing computing capacity by a factor of 10.

KLD Senior Research Analyst Andrew Brengle was one of five judges for this year’s SB20. “As tough as it is to narrow down the choices and find consensus among the judges as to which companies are the 20 best, it is nevertheless a rewarding process,” he said. “Every year I learn about several new companies that are doing great work, and every year the field of choices gets better.”

Click here to learn more about SB20 selection criteria and judges.

Also see read the press release and short descriptions of all the SB20 companies.