IPAC-NG is the iptables/ipchains based IP accounting package for Linux. It collects, summarizes, and nicely displays IP accounting data. Ipchains and (preferably) iptables are supported. Logs are stored in files, a gdbm or a PostgreSQL database.
JNFA - is a netflow analyzer. It uses MySQL database to store accounting information. Filters, used in the JNFA, allows very flexible classificate any kind of traffic and store it in the differend fields in database.
AccounteX is an IP accounting system based on the IP Stat program. It has many exciting features like fully customizable web traffic accounting and user access control by many different values. information service and web statistics and administration.