No. See any of the papers, eg http://ssrg.nicta.com.au/publications/nictaabstracts/Elphinstone_Heiser_13.abstract.pml http://ssrg.nicta.com.au/publications/nict

No. See any of the papers, eg http://ssrg.nicta.com.au/publications/nictaabstracts/Elphinstone_Heiser_13.abstract.pml http://ssrg.nicta.com.au/publications/nictaabstracts/Elphins.... The maintenance effort is quite reasonable. They've managed to evolve, and continue to evolve, the kernel even with the ever more stricter properties proven about it.