I'd like to try on my hosting the demo of your forum to see if I served, I can not install instalarmelo I would like to have if what I want, I've noticed that you have to pay money Download it but I want to get a demo the forum and look at the structure of codes to design myself.

There is no fee for YAF. It is opensource and community supported.

You can make a donation to help support the project but it is free to use within means of the GPL.