Phillip started off in academia, receiving a PhD in video filesystem design from Lancaster University in 1993. He subsequently carried out post-doctoral research at Lancaster and Cambridge Universities in the areas of video filesystems and multimedia operating systems. Since leaving academia Phillip has worked as a Linux kernel engineer mainly in the embedded industry (STBs, mobile phones), porting the Linux kernel to unsupported PowerPC variants, and writing numerous Linux device drivers. Phillip also recently served as a kernel maintainer for the Ubuntu distribution.
Phillip is probably most widely known in embedded Linux circles as the author and maintainer of the Squashfs filesystem, which was mainlined in 2.6.29.