15. RFC 3875
The Common Gateway Interface (CGI) [22] allows an HTTP [1], [4] server
and a CGI script to share responsibility for responding to client requests.
49. $blog = new SilexApplication();$blog->get('/',
function () {
return 'This is the blog!';});$app = new
StackUrlMap($app, [
'/blog' => $blog,]);
UrlMap
50. $app = new CallableHttpKernel(function ($request) {
$session = $request->getSession();
...});$app = new StackSession($app);
Session