I am running Zend Studio 5.5 on the mac without any issues. Well.... It is a bit slow when using the scroll wheel to scroll through a long file. Thanks, -- Joseph Crawford Jr. Zend Certified Engineer Codebowl Solutions, Inc. http://www.codebowl.com/ Blog: http://www.josephcrawford.com/ 1-802-671-2021 codebowl at gmail.com