Kroah-Hartman complained in his keynote address that Canonical released only 100 patches to the kernel in the last three years. (At a previous Google conference he had mentioned only six patches over five years.) He went on to say that in the same timeframe, a total of 100,000 were made to the kernel, Canonical's contribution therefore amounting to a mere 0.1 percent of the total. The result, he says, is that Canonical ranks in 79th place, way behind Red Hat (first place) and Novell (second place). In subsequent slides he tried to show how little code Ubuntu contributed to the "Linux ecosystem" and then went on to the real subject of his address.

The response from Ubuntu followed promptly: Matt Zimmerman, the Ubuntu CEO, found Kroah-Harman's claims "objectionable" and that his statistical methods were not an "exact science." Zimmerman admitted that Canonical did not contribute as many patches as Red Hat and Novell, but never claimed that it did. The Ubuntu kernel consisted primarily of original Linux kernel code. Zimmerman objected primarily to Kroah-Hartman's definition of "Linux ecosystem," finding it "odd" in that he included GCC, binutils, X.org and Glibc in with the Linux kernel. Also, "He disregards most of the desktop stack (including GNOME and KDE), all desktop and server applications, and most anything else that is recognizable to an end user as 'Linux'." Not least of all, Zimmerman accused Kroah-Hartman of failing to acknowledge his link with Novell, a key Canonical competitor. He suggested opening a dialogue on the keynote address matter in light of the fact that he had never been consulted previously on it.

Kroah-Hartman provoked further reactions in blogs and forums, such as one from Dustin Kirkland. The Linux Plumber Conference attracts developers at the Linux Kernel summit meeting in Portland, Oregon that belong to projects tightly linked to kernel development, such as X.Org and GCC.