The SVN::Web interface gives you access to the svn blame annotation(s) on files.
When you're viewing a specific file, you should see "Blame/Annotate" as one of the links in the upper left. When you click on it, you have a much more-marked-up rendition of the file, with blocks in alternating colors. These delinate where contiguous blocks belonging to a given rev start and end. To the left are the user-names of the users whose commits were responsible for a given block, and to the left of that a linked number indicating the revision that the particular block stems from. Clicking on the link will take you to the revision-view page, that lists all the files changed in that revision, along with color-coded diffs of the files/changes themselves.