I haven't seen a post about this and thought it worth's it.
Very simple program to use and very efficient for connecting in
Multiplayer sessions users across the three platforms : FSX Boxed/FSX Steam/P3D !...
People's comments are great, much more stable MP than default FSX, there is no "host"
concept and no server is needed. It may unite the "broken" FS community currently devided
to 3 platforms... SOH has a Teamspeak server, so JoinFS may "untie hands" for people
wishing to fly MP with others in a very simple way of doing it...
more info about JoinFS here