If you read Dave Miller (http://en.wikipedia.org/wiki/David_S._Miller)'s post that Cantrill responds to (http://cryptnet.net/mirrors/texts/kissedagirl.html), it's a really well researched critique of Solaris SPARC performance, justifying the existence of a port of the Linux kernel for that platform. Cantrill's job title was 'Solaris Performance', so Sun and Cantrill looked pretty poor by responding with a personal attack.