PHPHP

PHPHP is a self-hosted interpreter of tiny subset of PHP implemented in pure PHP.

Requirements

• PHP 8.4

Installation

No runtime dependencies!

Usage

php index.php

It will output the following:

Running on PHP
Running on PHPHP on PHP
Running on PHPHP on PHPHP on PHP
Hello, World!

The script, hello.php, is executed on PHPHP on PHPHP on PHP.

PHPHP on PHPHP on PHPHP on PHP

Edit this line as the following:

 if (defined('PHPHP')) {
-    if (PHPHP < 2) {
+    if (PHPHP < 3) {
         echo "Running" . str_repeat(" on PHPHP", PHPHP) . " on PHP\n";

Then, execute index.php. I recommend that you enable JIT.

php -d opcache.enable_cli=on -d opcache.jit=on -d opcache.jit_buffer_size=1G index.php

It will execute hello world on PHPHP on PHPHP on PHPHP on PHP.

Running on PHP
Running on PHPHP on PHP
Running on PHPHP on PHPHP on PHP
Running on PHPHP on PHPHP on PHPHP on PHP
Hello, World!

Talks

Talk in PHPerKaigi 2025 (in Japanese)

License

See LICENSE.