Alexander was mostly involved in QEMU, KVM and openSUSE on ARM during the last few years. Whenever something really useful comes to his mind, he tends to implement it. Among others he did Mac OS X virtualization using KVM, nested SVM, KVM on PowerPC and a lot of work in QEMU for openSUSE on ARM. He is an upstream maintainer of KVM for PowerPC, QEMU for PowerPC and QEMU for S390x.