Have you ever needed to quickly sketch out a concept for Minecraft? We may have found the answer to your problem.
Minedraft is a web application created by Alex Cline that allows you to quickly and easily prototype your creations. This allows for much larger and complex creations to be designed without the headache!
There are a plethora of blocks that you can use, as well as mobs and other well-known Minecraft creatures that will complete the look.
When you're ready to show off your creation, Minedraft provides you with a link to share your creations with others. Here's the URL for one that we've made above: http://minedraft.net...7f79220b4000002
Well I have recenly been using a 3D planer called minecraftstructureplanner and it is pretty good accept fot the fact that it is TOATALY OUTDATEDSo when this came out I was really happy about it ( although, it would be good if it was 3 dimensional)
You could try one of my project, MineCanvas (very similar to MineDraft but offers more performance and can join multiplayer to draw together real time.) The flaw about MineCanvas is that its UI can be confusing, and it doesn't have blocks like Emerald and Halloween updates (anvil, nether star, etc) but it works.
It can't lag... It is just a click and drag. Also, this isn't Terraria, it is supposed to help you visualize your creations before you build them. Also: Great tool!
It does lag. Lags too much. Poorly coded website I'm afraid to say. Looks great on outside, runs bad on inside. It locks up the browser for few seconds right before when you drag when there is already alot of blocks (like 20 blocks+) on it. It shouldn't have to lag when you click and drag. That is so 1998's. This is 2012 where website can be really fast and be responsive while drawing on any modern browsers IF you code it right.
Interesting thing to note: It doesn't lag in IE, but does lag in all other major browsers. This developer may be using IE-optimized scripts for MineDraft.net.
It's too bad that MineDraft.net doesn't get updated anymore.
This is why I started my own project, MineCanvas, that rivals MineDraft.net by offering faster performance and newer contents. If nobody bothers updating it, someone has to create a better one and that would be me!