Hi,

Actually, as already pointed out in a previous post, since older versions are not maintained any more, you should upgrade to the latest version (5.x).
You can download the latest Lightstreamer Moderato version at http://www.lightstreamer.com/download and you can use it for free even in production environments and does not require any license key.
Anyway, you may contact info@lightstreamer.com for any question or doubt about licenses or for general enquiries on Lightstreamer and for sales information.

hth
Marco