Download of DevBrowse 1.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. This free Mac application was originally designed by Freddy Heppell. The program lies within Developer Tools, more precisely Webmaster Tools.
From the developer:
DevBrowse is a browser designed for website testing. The application follows basic HTML standards. With this program, you can easily see how your site will look in old browsers. If your website looks fine in this browser it should look fine in others.
You may want to check out more software for Mac, such as AcidSearch Installer, RAGE WebDesign or solr, which might be related to DevBrowse.