This suit is probably in retaliation for an earlier Corel suit against Microsoft this summer. http://www.fosspatents.com/2015/07/corel-software-sues-microsoft-

This suit is probably in retaliation for an earlier Corel suit against Microsoft this summer. http://www.fosspatents.com/2015/07/corel-software-sues-microsoft-for.html http://www.fosspatents.com/2015/07/corel-software-sues-micro.... This one reason companies keep a war-chest of patents, so they can fight back when targeted with a dying company's portfolio.