This image is based on Alpine Linux image, which is only a 5MB image, and contains PHP programming language.
This image is only 17MB on disk.
NOTE: This image is not really intended for a site hosting use-case. It is created to run pure PHP code from a shell.
$ docker run --rm frolvlad/alpine-php php -r 'echo "Hello World";'
Once you have run this command you will get printed 'Hello World' from PHP!