Theodore Ts'o was the first North American Linux Kernel Developer, and organizes the Annual Linux Kernel Developer's Summit, which brings together the top 75 Linux Kernel Developers from all over the world for an annual face-to-face meeting. He was a founding board member of the Free Standards Group, and was chair of that organization until it merged with OSDL to form the Linux Foundation. He is one of the core maintainers for the ext2, ext3, and ext4 filesystems, and is the primary author and maintainer for e2fsprogs, the userspace utilities for the ext2/3/4 filesystems. At IBM, Theodore served as the architect for the Real-Time Linux development team.