Modlogan is a modular logfile analyzer which is currently able to parse ftp-, webserver and squid logs. The generated output can be viewed by a webbrowser (->moglogan, webalizer) or your favorite text editor (->text). The template engine allows you to create the output with your prefered look and feel.
The different input and output modes are provided by some surrounding plugins. For example the modlogan output plugin provides three different menu structures for the same colourfull output while the output which is generated by the webalizer output plugin looks similar to the output generated by the original Webalizer known from webalizer.
The input is handled the same way. One plugin is for the web server logs, the next is for xferlog from FTP-servers like WuFTP and some others are for mail-servers, streaming-server and so on.
The last stable version of modlogan was 0.8.13. It works well for many users even under high load with large (some Gbyte) logfiles.
Notheless, modlogan is not maintained anymore. The author is now working on lighttpd, a web-server.