Greg Kroah-Hartman (GKH) is a major Linux kernel developer. As of April 2013 he is the Linux kernel maintainer for the -stable branch, the staging subsystem, USB, driver core, debugfs, kref, kobject, and the sysfs kernel subsystems, Userspace I/O (with Hans J. Koch), and TTY layer. He also created linux-hotplug, the udev project, and the Linux Driver Project. He worked for Novell in the SUSE Labs division and, as of 1 February 2012, works at the Linux Foundation.