Note this project is outdated and no longer maintained by the owner. There's another project, which has similar porpuse, callled Minecraft Command API. I recommend contribute to the new project.

Since 13w36a it is possible to summon entities using the /summon Command. Unfortunately Mojang does not offer a big support for this. This website is here for helping you with your summon commands without writing long lines of codes

1. Install NodeJS
2. Run npm install to install the dependencies
3. Run npm run start to start the application

Not many rules except it must work. I literally don't care, because the whole project is a mess and hacked together. So feel free to create pull request and contribute.

Beware; really ugly code. I began this project when I was 13 years old. Good luck!