Here's a slide deck postmortem: http://www.slideshare.net/andreizm/the-good-the-bad-and-the-ugly-what-happened-to-unicode-and-php-6 http://www.slideshare.net/an

Here's a slide deck postmortem: http://www.slideshare.net/andreizm/the-good-the-bad-and-the-ugly-what-happened-to-unicode-and-php-6 http://www.slideshare.net/andreizm/the-good-the-bad-and-the-... tl;dr: They made some bad decisions about Unicode and everyone got burned out. They skipped 6 because 7 contains none of the Unicode changes and didn't want to confuse people.