This is a Vim plugin which simply makes a silent curl request to localhost:7700/reload whenever Vim emits a BufWritePost autocmd event. The idea is that you can then install the corresponding Chrome extension, chrome-stay-fresh, which listens for those requests and triggers a reload in whichever Chrome tabs are configured to respond.

For those interested, the vim-hooks plugin generalizes on this concept and allows you to hook any script into any Vim autocmd event. A one-line script which simply ran curl localhost:7700/reload on BufWritePost events is one specific example that would be functionally the same as installing this plugin, though you can no doubt imagine many other sorts of scripts, or sets of scripts, which could be used to achieve more complicated ends.

If you don't have a preferred installation method, I recommend installing pathogen.vim, and then simply copy and paste:

cd ~/.vim/bundle
git clone https://github.com/ahw/vim-stay-fresh.git

Of course in order for anything interesting to happen, you must also install chrome-stay-fresh, and detailed instructions on how to do so are available at that link.

vim-stay-fresh just makes HTTP requests to localhost:7700, which the native host process is already listening to. So, no further set up is required. Click the extension's icon in the browser toolbar to toggle whether or not that tab reacts to reload requests.

The command ssh your.server.com -R 7700:localhost:7700 will enable remote port forwarding, which means that all requests made to port 7700 on your.server.com will be sent through an SSH tunnel to your client machine, which will then just forward that request to the client's localhost:7700. Voila. You can set up your ~/.ssh/config file as follows in order to avoid having to remember to add the remote port forwarding argument all the time.

Host your.server.com
  HostName 12.34.56.78
  User sarah
  RemoteForward 7700 localhost:7700