Yes, it is.
You can read the full details in the agreement that you accept by downloading Lightstreamer Moderato:
http://www.lightstreamer.com/distros/Lightstreamer_Moderato_5_1_1_Colosseo_20131009/Lightstreamer/Software%20License%20Agreement.pdf
You can learn about the limitations of the Moderato edition in the product matrix:
http://www.lightstreamer.com/products
For example, you get max 1 update per second for each subscribed item in the page; and you only get the JavaScript client library (anche the Flash bridge, if needed).