Shoutbox

I am making a forum i need some help:

Heres what i need help with:

• Are you alloud to upload msgplus scripts to a forum?
  Can you get the direct download link for msgplus4 and then put it on?
  What is a mirror?

The subject of my forum is internet sites,scripts,animation.computing dose any one have suggestions for it?

Can anyone suggest forum sites that is good.
Is phpbb the best i heard of that?

Thanks,

kni