JoinFS (GA VFR Flying)
GFSG have historically used JoinFS (which is now no longer developed or supported) as their preferred multi-player online connectivity software and currently will remain the preferred software for VFR flying.
Links
JoinFS software download - JoinFS 
X-Flightserver.net (Commercial Jets)
X-Flight-server.net is kindly sponsored by X-Plane.org and is a server platform that provides similar infrastructure to VATSIM and IVAO, without having to use interactive ATC. There are two parts to using this software which will require you to create an account at X-Flightserver.net and then to download and install the Swift Pilot Client.
Links
X-Flightserver.net account creation - Signup (save your credentials!)
Swift Pilot Client software download - Version 0.15.46 (check for updates!)
Swift Project documentation - Swift Pilot Client (suggest read first)
Swift Project video tutorials - Video Tutorials (suggest read the manual first)
Displaying X-FlightServer traffic in Little Navmap - How to configure
Need Assistance?
If you require assitance with getting up and running with any of the above software packages (including TeamSpeak), please feel free to request assistance.
You can contact us using the following email link. Remember to state the type of assistance required, so that the appropriate person can help you.