There may be more, but we are aware of our customers having created the following wrappers for LeanKit's API in order to simplify integration. If you know of another one please let us know so we can share the information!

Python

The project can be found at: 
https://launchpad.net/lp2kanban

The specific code for calling the API is found in this file: 
http://bazaar.launchpad.net/~launchpad/lp2kanban/trunk/view/head:/src/lp2kanban/kanban.py

Ruby

https://github.com/mlainez/leankitkanban

JIRA (Ruby)

https://github.com/limadelic/akira

.Net

https://github.com/stack72/LeanKitKanbanCaller

Telnet

Example for potential equipment to LeanKit integration. 
http://support.leankitkanban.com/entries/20851792-telnet-integratio...