The ISC Dynamic Host Configuration Protocol Distribution provides a
freely redistributable reference implementation of all aspects of the
DHCP protocol, through a suite of DHCP tools:

  * A DHCP server
  * A DHCP client (this port)
  * A DHCP relay agent

Version 3 of the ISC DHCP Distribution includes the following features
that are new since version 2.0:

  * DHCP Failover Protocol support
  * OMAPI, an API for accessing and modifying the DHCP server and client state
  * Conditional behaviour
  * Storing arbitrary information on leases
  * Address pools with access control
  * Client classing
  * Address allocation restriction by class
  * Relay agent information option support 
  * Dynamic DNS updates
  * Many bug fixes, performance enhancements, and minor new DHCP protocol
    features. 

WWW: http://www.isc.org/products/DHCP/