the migration from v4 to v5 went ok, considering there was a large blog campaign against end-of-lifing php v4 (I remember Matt Mullenweg, amongst many other blo

the migration from v4 to v5 went ok, considering there was a large blog campaign against end-of-lifing php v4 (I remember Matt Mullenweg, amongst many other bloggers and hosting companies, had the badge in their blog sidebars) and there was a lot of resistance to it. The big thing with PHPv5 was not just having to migrate code, but even at the time v4 was no longer supported and v5 had been out for years in benchmarks v4 was still 20-30% faster then v5. v5 to v6 could be a similarly smaller scale migration. The number of backwards incompatible changes in 4 to 5 wasn't long: http://www.php.net/manual/en/migration5.incompatible.php http://www.php.net/manual/en/migration5.incompatible.php Slashdot thread from the time with some details on the resistance: http://beta.slashdot.org/story/87591 http://beta.slashdot.org/story/87591 Migrating from v3 to v4 was also a backwards incompatible leap: http://www.physnet.uni-hamburg.de/physnet/php/migration4.html http://www.physnet.uni-hamburg.de/physnet/php/migration4.htm... So the PHP project has pulled it off twice already, perhaps they don't get enough credit for that.