Swagger Editor lets you edit Swagger API specifications in YAML inside your browser and to preview documentations in real time. Valid Swagger JSON descriptions can then be generated and used with the full Swagger tooling (code generation, documentation, etc).
Make sure you have Node.js installed.
git clone https://github.com/swagger-api/swagger-editor.git
cd swagger-editor
npm start
To run on a Ubuntu 14.04+ box,
sudo -s
apt-get update && apt-get install -y git npm nodejs
ln -s /usr/bin/nodejs /usr/local/bin/node
npm install
npm install -g bower grunt-cli
bower --allow-root install
grunt --force build
grunt connect:dist