The following working implementations exist at this moment. Most are under very active development..

Cisco: IOS / NX-OS

Suitable for most Cisco ISR, ISRG2, ASR1K, and Nexus 7000 Routers

lisp.cisco.com   (A and AAAA)

www.cisco.com/go/lisp

OpenLISP: OpenLISP.org

Runs on FreeBSD

LISPmob: LISPmob.org

Runs on Linux

Aless: Linux 2.6 implementation

Includes iproute2-lisp and lispd