First of all, thank to show your interest for my project. I know my license is really far to be good and I don’t very appreciate that. At the beginning it was the only way that I find to protect my project. I will take your advice and I will change for an open-source license.
I know decompiling the jar doesn’t count like documentation. I’m currently writing the documentation for the project. I will update the post when it will be ready to use for the devs.
I updated the project. It’s now under the GPLv3 license.
Link to the project:
This is amazing, cant wait to see where this goes, sooooo many possibilities. i you make this plugin dummy-friendly, i cant code 
soo i wont know how to implement its API in other plugins
Thank you to @NickG365 to have ported my project to Bukkit/Spigot.
Let me just nail this down.
I can put the mod onto my server and players will not need it to join?
But if they wish to see the interface then they will need the client side mod correct?
Yes, you can put the plugin on the server and the players don’t need the mod to join the server. If the player want to use the interfaces, he need the mod on his client.
Thank you very much 
Hi, have your GUI the ability to be used as a man statistic site for the admins?
Will it have a WEB interface too?
Thanks.
My project allow you to create interface on the Minecraft client. You can’t create interface for the web.
OK thanks. Maybe you enhance it later with web interface too. 
The wiki is finally here! It contain all the informations to help you to implement MinecraftGui to your project. I will add a section with some tips to help you in the next month.
The javadoc is online, it contain all the classes and the methods you need.
MinecraftGui now supports the latest version of Sponge.
To do list:
I’m currently searching developers who would like to implement MinecraftGUI on their project. I will help to create and implement everything to ease your work.
I like where this is going. Nice job so far!
in-game web browser?
The problem with an in-game web browser, it’s a lot of work to do. All the html tags, the css attributes and the javascript support. Its standardized by the W3C and it’s a lot of details.
Why to do something totally usefull like web browser, when there is so much amazing things that can be done ?
This would require incredibe amount of work. Implementing plain html might be easy (html page into pixel buffer and render it as a texture) but well it wont be dynamic, which means useless.
Instead of writing your own browser you could just embed one.
I’m not planning to create my own browser and I looked for a browser and I haven’t found one that support lwjgl.
http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/1291044-web-displays-browse-on-the-internet-in-minecraft Manages to do it. But because of the licensing the mod is under…
This is why I like Open Source… It’s one thing the Bukkit community largely got right.
This mod only allow you to go on the internet, you can’t interact with the server but I would have liked to see how he managed to do it.