I managed to put this one together pretty quickly.
This one grabs the Lua scripts (used by the Start Server & Start Player buttons) from the website using the loadfile function, and executes them with arguments obtained by the GUI.
Functions (Notice, they should have http:// before them)
Start Server:
loadfile(“http://www.roblox.com/game/gameserver.ashx”)(0,53640)
Starts a Roblox Server with the placeId as 0 and the host’s port as 53640
Join Server:
loadfile(“http://www.roblox.com/game/join.ashx?UserID=0&serverPort=53640&server=localhost”)
Makes studio start a client join under the UserID of 0, with the server port being 53640 and the serverIP being the localhost.
Why beta? I haven’t been able to successfully connect my friend to one of my servers yet, so I’m not too sure if this works completely yet. I am using the correct arguments though & it works if I host/join a server locally. So I think it should work if you actually know how to open the port for your server (unlike me :P)
Have fun!