It is mostly a wrapper around `rsync`. Additionally it will maintain an archive of posts for each year, and the latest 5 posts on your gemlog homepage.
1. You are using MacOS locally and a unix-like OS on the server (it probably works on n*x locally but I haven't tested it)
2. If you have text _under_ the list of latest posts on your homepage, you have at least 5 posts listed already (I could have put in some logic to deal with this but I am lazy)
4. You have read and write permission for your gemlog files on the server, with the same username as your local machine (otherwise file permissions get weird)
5. You have permission to install files at `/usr/local/bin` on your local machine
*`remote_dir` - the SSH remote directory path to your files on the server. This includes the server name or ip address, so should look something like `gemini-server:/srv/gemini/example.com` or `username@123.456.789:/srv/gemini/example.com`.
*`editor` - the command to open the text editor you want to use. Defaults to `nano`.