I think I saw a post from the guy who wrote pG here, so I thought I'd mention this.
I've been using pG 1.6 to good effect, but last night I downloaded pG 1.7. It was much, much faster. Good work, whoever you are. Looking at TG2 has given me some ideas for mods to the program that I think might be good.
Yay! I love Planetgenesis! Being on a Mac, it's the only heightfield generation tool I've ever really been able to use.
Thanks for the kind word folks.
I though you might like to know that pG 1.8 is going to have a extra Worley noise that is around 2 x faster than Cache Worley at the expense of a bit of randomness (nothing you would be likely to notice though).