perl-total-connect-comfort
A Perl module that wraps the Honeywell Total Connect Comfort API. Allows you to query room temperatures and view other details like setpoints.
Usage
Call the test script with ./test_api.pl username password (don't forget to single quote that password if it contains symbols).
Cacti
Also includes Cacti scripts and templates to make setting up Cacti monitoring simple.
I've written a Cacti setup guide (because sadly it's not that simple).