On Developpez.com, I'm looking for information on setting up a basic Express.js application. Can you find the common command used to install Express.js and a simple code example that creates an Express application instance to set up a server? Provide both the command and the code snippet.
Navigate to 'https://www.developpez.com/' Click on the 'Dév. Web' link. On the 'Dév. Web' page, click on the 'NodeJS' link. From the Node.js section, click on the 'Tutoriels' link. Click on the tutorial titled 'Apprendre la programmation en JavaScript avec le framework Node.js'. Within the article, navigate to the 'III. Un site web bien architecturé avec Express' section by clicking its link in the table of contents. Locate the 'III-A. Installation de Express' subsection and identify the installation command. Locate the 'III-B. Une application basique avec Express' subsection and identify the basic code snippet for creating an Express application instance. State the identified installation command and the code snippet.
Successfully navigate to the Node.js tutorials section. Successfully navigate to the 'Apprendre la programmation en JavaScript avec le framework Node.js' article. Identify and state the Express.js installation command as 'npm install express'. Identify and state the basic code snippet for creating an Express application instance and setting up a server, which should be:
```javascript
var express = require('express');
var app = express();

app.get('/', function(req, res){
  res.send('Hello World');
});

app.listen(3000);
```