I noticed this phrase in the license:
A single license of the Software must only be used on one computer simultaneously.
I read this as saying that it’s OK for me to use Unity with just one license code on more than one computer, so long as I only use one at a time. Specifically, I’d like to install a copy at work as well as at home so that I can tinker with it during my lunch break. Is this allowable?
The Neil Carter? The one with the cool characters and of Yoink! fame? Cool! I can’t wait to see what you start creating with Unity. man, there are some cool people hanging out here. Welcome!
Regarding this. Is the license floating? can i work on different machines as long as i have 1 instance open at a time?
Thanks.
Yes. It is. As long as the software is only being used on one machine at a time. Our activation system will allow up to two activations per serial number by default. The reason is exactly the case you mention above (one computer at home, one at work) or people who have a laptop and a desktop machine.
Woohoo, I’m famous! 
Yup, that’s me. Thanks for the vote of confidence! I’ve already got some interesting things going on with Unity… hopefully I’ll have something to show fairly soon.
That sounds perfect. One question: what happens if I get a new computer (at work or at home)? Do I need to somehow unregister a previous computer?
It is not possible to unregister a machine. You will have to contact us in that case and get us to pull the relevant levers. (Ie. allow more activations.)
Thanks for that clarification. 
Only two activations, interesting I was told it was 3 by one of you guys. Anyhow you will be hearing from me next time I upgrade Thanks for the confidence of at least two. Jeff
Oh… yes… I remembered incorrectly it is 3 times. (And not really 3 times, but on 3 different machines. You can always reactivate on a machine that already has been activated.)