SubethaEdit is a cool tool that allows people to write a single document collaboratively. Amazingly efficient to jot down some notes during a meeting.

Setting collaborative editing is a piece of cake when people are in the same room thanks to Bonjour. But the setup for remote editing over the internet isn't that easy, as it requires the Mac that acts as a server to accept incoming connections, and therefore requires some router and firewall tweaks, which is not always easy nor even possible.

So here's a little trick that allows you use SubethaEdit from anywhere, if you own a Unix box connected to the internet and can connect to it using ssh.

One-time configuration of the Unix box (say it is at mybox.com)

• Configure the firewall to allow incoming connections on TCP port 6942 (e.g. "iptables -t filter -A INPUT -p tcp --dport 6942 -j ACCEPT")
• Allow remote hosts to connect to ports forwarded by ssh by adding "GatewayPorts clientspecified" in /etc/ssh/sshd_config)

On the Mac, when you want to subethaedit:

• Connect to the box and forward remote port 6942 to the Mac:
  ssh -R '*:6942:localhost:6942' mybox.com
• Start SubethaEdit, select "File/Announce," then "File/Copy Document URL"
• Paste the URL somewhere, it should look like see://mymac.local/document.txt?documentID=54D0983E-78A5-4273-9281-122898470BD2
• Replace "mymac.local" with "mybox.com" in the URL and give it to your friends so that they can connect to your local document!

Happy collaborative editing! A killer to take notes during a voice meeting over Skype or VoIP!