Have a cool server, but wish more people could see it from the comfort of their web browser? WebSandboxMC allows modern web browsers to view and interact with a small part of your server's world using WebGL and HTML5 technologies:

See also: https://www.spigotmc.org/resources/websandboxmc.39415/
Currently supports:
WebSandboxMC embeds a copy of NetCraft, online demo: https://satoshinm.github.io/NetCraft/ (you can connect to a WebSandboxMC server by typing /online servername)
Official test servers: feel free to stop by and say hello! (chat is enabled)
Once the plugin is installed, visit the URL printed in the server log on startup to load the client and automatically connect to your server.
Release downloads: https://github.com/satoshinm/WebSandboxMC/releases (also available at Spigot Resources: https://www.spigotmc.org/resources/websandboxmc.39415/)
Documentation/source: https://github.com/satoshinm/WebSandboxMC
Issue tracker: https://github.com/satoshinm/WebSandboxMC/issues
Disclaimer: This plugin is early in development, there may be bugs and/or missing features. Use at your own risk, but high-quality issue reports and code contributions very welcome.