$ git clone git://github.com/fruit/php-extension-sm.git
$ cd php-extension-sm
$ phpize
$ ./configure --with-sm
$ make
# make install
Than add new line to the php.ini and restart Apache/PHP-FPM
extension=sm.so
<?php
# prints: 0.66666666666667
print strike_match("Hello, World!", "hello world");
Version PHP 5.2, 5.3, 5.4, 5.5, 5.6
Version PHP 7.0 (unlikely)