Share Your Single Player Minecraft World with Friends
A new feature in the latest snapshot allows you to share your single player world with other players over LAN. There is no knowledge on how to configure a server required - just the ability to run “/publish”.
If you had wanted to do this before the command was added then you would have had to download the Minecraft server software, configure it and then copied across your world files from single player.
As mentioned in a blog post by Mojang, the new feature is “still very much work in progress” so there is no guarantee that it will work perfectly. The blog post also mentioned that they will likely add options to edit things like what game mode players who join your world will get. We have tried this locally and it seems to work great.
Be sure to watch this space for any more information about the sharing feature.