For Autoptimize 2.0.1 I declared a pretty complex regex to extract font-face’s from CSS using the nowdoc-syntax which is supported from PHP 5.3 onwards. Taking into account that the first PHP 5.2 release was over 9 years ago and support ended with the release of 5.2.17, over 5 years ago I assumed using a nowdoc would not be a problem for anyone. How naive I was; several people contacted me with this ugly error-message PHP 5.2 throws;
Parse error: syntax error, unexpected T_SL in /wp-content/plugins/autoptimize/classes/autoptimizeStyles.php on line 396
There is a workaround and even a more fundamental fix for that already, but who would still want to run PHP 5.2, which has this huge list of security issues? Moreover PHP 5.5 and 5.6 seem approximately twice as fast as 5.2 according to these test results and PHP 7.0 is even over three times as fast as 5.2! And still almost 9% of all WordPress sites are running on that old version (so I could have known this was coming really, bugger).
I you are one of those, do urge your hosting company to urgently provide you with an upgrade path to PHP 5.6 (or even 7.0)!