hello, I have a little question. We have a server trought hamachi, and qe want install any mod like buildcraft or any others (kaevator... etc) The question is the following:

is there any way to download it only that keeps the server? or we have to download it individually?

i supose that everyone must have this mod... but what if one of us do not have it installed? how you see those buildings?

if anyone can help me, please tell me Step by Step, both for the one who keeps the server and player

many thanks!