Rich, Just to follow up. First a disclaimer, I am neither expert with nor an advocate of svn Tortoise under windows. My teams at NASA use svn under Linux, and the command line version is what I am familiar with. WIth the command line svn it is easy to generate a diff file between any two revisions, it's a single command. Having said that, with a half hour of experimentation, I found that Jonathan has made a tag for each fractint patch he has released, and Tortoise has a revision graph capability that will show you graphically which svn repository revision corresponds to which tag. Tortoise has the capability to change your working area to any particular repository revision, and to show a diff between your files and the repository. None of that quite adds up to creating a diff between revisions in a straight forward way, but it's close. I imagine one could make a work area at the revision corresponding If somebody knows more about svn under Windows maybe they could chime in. Rich, how is this svn set up at your Fractint for WIndows site? Tim