Advanced Web Statistics (AWStats) is a free powerful Web server logfile analyzer (Perl script) that shows you all your Web statistics including visits, unique visitors, pages, hits, rush hours, search engines, keywords used to find your site, robots, broken links, and more. It works with both IIS 5.0+ and Apache Web server log files as a CGI and/or from the command line. It also supports around 40 languages.
pmacct is a small set of passive network monitoring tools to account, filter, classify, aggregate, and export IPv4 and IPv6 traffic. A pluggable and flexible architecture allows storing collected network data in memory tables, RDBMSs (MySQL, SQLite, PostgreSQL, BDB), and flat files, and also export via IPFIX, NetFlow, or sFlow protocols to remote collectors. pmacct features fully customizable historical data breakdown, sampling, BGP correlation, tagging, and triggers. Libpcap, ULOG, sFlow v2/v4/v5, NetFlow v1/v5/v7/v8/v9, and IPFIX are supported data capturing methods.
Performance Co-Pilot (PCP) is a framework and set of services for supporting system-level performance monitoring and performance management. It provides a unifying abstraction for all of the interesting performance data in a system, and allows client applications to easily retrieve and process any subset of that data using a single API. A client-server architecture allows multiple clients to monitor the same host, and a single client to monitor multiple hosts. Archive logging and replay are integrated so that a client application can use the same API to process real-time data from a host or historical data from an archive.
GoAccess is a real-time Web log analyzer and interactive viewer for almost every Web server. It runs in a terminal and provides fast and valuable HTTP statistics for system administrators that require log monitoring and visual reports on the fly. GoAccess can monitor unique visitors, browsers, spiders, OS, hosts and IP geolocation, keyphrases, referring sites, status codes, etc. It has support for IPv6 and it parses nearly any Web log format.
BBclone is a PHP Web counter on steroids which displays individual logs as well as aggregated data. It is a clone of Big Brother webstats, except that it is written in PHP and it relies only on flat files (no database needed). BBclone enables any Web site administrator to have a very precise view of who visit the website: OS, browser, date, referring page etc. Main features include reload resistance, hostname resolution, proxy workaround, and blacklist.