Do you have a bunch of VPN syslogs or IIS logs that you'd like to create a report on usage/users?
Then you need Sawmill.
Here are the logs it will automatically recognize & create a formatted report with graphs.
However, it is only available free as a 30 or 60 day trial.
At one time you could build up credits to get it free, by providing feedback, but sadly they seem to have removed this option.