BrowserCounter 1.3.0 is a small (well, ok, not that small) Perl program (NOT a CGI) that scans any standard 'combined' (ECLF) format web log and produces a table summarizing what browsers people have used to access a web server.
You will need the GD::Graph module if you want the Pie Charts (available from CPAN or PPM repositories). The progam will still run without it - you just won't get any pie charts.
An example of a report is available. You can get the script (right-click to save it) here as well. A sample configuration file is also available. The configuration file is only necessary if you want to change the report layout or options.
If you like and use this program - let me know - I would LOVE to hear about it.