The following is our offer of free software. Please check if any of those tools are of use to you. We also like to hear about any of your successes, bug reports or feature request. Since it's free, we can't promise anything, but we'll try our best when we see a chance to improve.
Free download of our lighting design toolkit.
Existing users may rather want the updates.
Stuff for using with Radiance. This section is most interesting for people who want to work with Radiance directly, without the help of a graphical user interface.
A collection of tools to extend your modelling capabilities in
older versions of Autocad.
ALso for older versions: PyAcad (offsite link) - Autocad programming in Python.