Did you initially use JavaScript specifically in development?

Yes, JavaScript is the primary language for development in Node.js. Node.js is a JavaScript runtime environment outside the browser that allows you to run JS code on the server.

When developing with Node.js, you write in JavaScript, using its syntax and features. This allows you to use a single language both on the client (in the browser) and on the server.

Example of a simple server in Node.js using JavaScript:

const http = require('http');

const server = http.createServer((req, res) => {
  res.writeHead(200, {'Content-Type': 'text/plain'});
  res.end('Hello, world!');
});

server.listen(3000, () => {
  console.log('Server running on port 3000');
});

Thus, JavaScript is the main development language in Node.js.