Prerequisites
Installing WebSVN
From the project's GitHub:
WebSVN offers a view onto your Subversion repositories that's been designed to reflect the Subversion methodology. You can view the log of any file or directory and see a list of all the files changed, added or deleted in any given revision. You can also view the differences between two versions of a file so as to see exactly what was changed in a particular revision.
If you receive errors about svn.exe or other svn commands failing, make sure the Subversion /bin directory is in the system path and that the user running the web server process has read access to the Subversion parent path specified in config.php