Pugs first came out in 2005, and by my count it was the third implementation of Perl 6. Rakudo's a couple of days away from its 31st release. Yes, Perl 6 should have had regular releases much earlier than 2005, but we've used iterative development for years.
http://www.joelonsoftware.com/articles/fog0000000017.html
However, Joel explicitly states this means you release early, and iterate.