OpenFPC is a set of tools that combine to provide a lightweight full-packet network traffic recorder & buffering system. It's design goal is to allow non-expert users to deploy a distributed network traffic recorder on COTS hardware while integrating into existing alert and log management tools.
OpenFPC is described as lightweight because it follows a different design model to other FPC/Network traffic forensic tools that I have seen. It doesn't provide a user with the ability to trigger automatic events (IDS-like functions), or set watch events for anomalous traffic changes (NBA-like functions) as it is assumed external open source, or comercial tools already provide this detection capability. OpenFPC fits in as a companion to provide extra (full packet/traffic stream) data as a bolt-on to these tools allowing deeper analysis of event data where required.
Simply give it a logfile entry in one of the supported formats, and it will provide you with the PCAP.
To understand how OpenFPC fits together, take a look at the About page.
If you're looking for up to date information on how OpenFPC is progressing, take a look here.