WebSchematics
WebSchematics lets you render Minecraft schematic files in the web, completely in the browser. It uses nbt.js to parse the schematic and converts block models from a resource pack into three.js meshes, before assembling them into a scene.

Still a work in progress, but it looks pretty neat! Check out the live demo—though note it only currently works with modern Sponge v3 (.schem) schematics, like the ones you can generate with WorldEdit.
License
WebSchematics is licensed under Apache-2.0. It uses the following libraries:
- three.js, released under MIT
- lodash, released under MIT
- pako.js, released under MIT
- nbt.js, released under the public domain
Minecraft textures and models are © Mojang A.B. and are not included in the source. You'll need to provide your own resource pack or fetch them remotely.