Checkout bpmn-js, cmmn-js and dmn-js if you search for our modeling toolkits.
These bpmn.io project website sources.
The site is built via npm and requires a setup Node.js environment.
Make sure you have the environment properly set up.
Build and serve the site on localhost:9000 via
npm run dev
Create a distribution ready version of the site via
npm run all
Fetch the results from the dist
folder.