Terrain Creation - Newbie Question

Greetings all.

Forgive a low level question:-

I used to use VistaPro to create pretty good landscapes generated by being able to input the fractal generator with a seed number of my choice, and it was pretty simple.

What is out there now that will give me the features that VistaPro has but provide a much higher quality stills output?
Which can accept a specific number to the fractal generator to create the world?

Thanks much - a steep learning curve for me!

world machine is a good option