* Honeyd

http://www.honeyd.org

Low interaction honeypot. Developed by Neils Provos.  Honeyd is a small daemon that creates virtual hosts on a network. The hosts can be configured to run arbitrary services, and their personality can be adapted so that they appear to be running certain operating systems.

* HoneyMole

http://www.honeynet-pt.org/index.php/HoneyMole

Secure Ethernet Bridge over TCP/IP, tunneling in a transparent, safe and easy way, network traffic to a remote location without the need of any kernel patches or modules, or even the need to hide routing in the honeypots. It can be used to easily deploy honeypot farms of distributed honeypots, transporting network traffic to a central honeypot architecture where data collection and analysis will be done.

* Nepenthes

http://nepenthes.mwcollect.org/

Tool to collect malware. It acts passively by emulating known vulnerabilities and downloading malware trying to exploit these vulnerabilities. Developed and maintained by the German Honeynet Project.

* General Honeynet tools

http://www.honeynet.org/tools/