Radar is a PSR-7 compliant Action-Domain-Responder (ADR) system. While it may look like a micro-framework, it is more like a wrapper around the real core of your application domain.
You will need Composer to install Radar.
Pick a project name, and use Composer to create it with Radar; here we create
one called example-project:
composer create-project radar/project example-project
Confirm the installation by changing into the project directory and starting the built-in PHP web server:
cd example-project
php -S localhost:8080 -t public/
You can then browse to http://localhost:8080/ and see JSON output:
{"phrase":"Hello world"}
You can also browse to http://localhost:8080/your-name and see modified JSON output:
{"phrase":"Hello your-name"}
You can read the documentation here.