Hi

If I install the free download unity3D can I later start the pro 30 days trial or will that start automatically?

Thanks

They prompt you to start the Unity Pro trial upon downloading and installing Unity. But the answer is, I think you can try the free program and later try the Pro trial.

Thanks. If I read correctly I can publish commercially until $100'000.- income per year with the free version? That's quite a bit and enough for me. I don't expect that much rush/income...

Yeah, they let you do a lot with the free version. The Pro version has a lot of added features but it's expensive at $1500. Of course, everything is halved in price if you go to college through the student discount, so $1500 for example becomes $750.