Hi, I was doing some google-ing and found a blorbiter addon (an addon that allows blender to convert to .msh format). The only problem I have is I have no idea how to get it to export. I have been using this page to help me a liitle bit. Does anybody know how to get it working right?

I wonder why the orbiter .msh is different from the battlefront .msh. Has any-body tried to use this orbiter mesh with battlefront?

the answer is: because the both developers incidentally chose the exstension .msh for their models.
game developers usually create new filetypes fitting the requirements of the engine/game. if they would use a filetype from another developer they would probably have to pay for the license plus it wouldnt fit their purpose perfectly.