Plan 9 was born in the same lab where Unix began. Underneath, though, lies a new kind of system, organized around communication and naming rather than files and processes. In Plan 9, distributed computing is a central premise, not an evolutionary add-on. The system relies on a uniform protocol to refer to and communicate with objects, whether they be data or processes, and whether or not they live on the same machine or even similar machines. A single paradigm (writing to named places) unifies all kinds of control and interprocess signaling.
Release Notes: Some fixes for a time sync related problem and minor feature enhancements.
Release Notes: New features and bugfixes were added. SDL now compiles and runs on Plan 9. However, SDL for Plan 9 has not been included in the operating system in this release.
Release Notes: Some new features and bugfixes. Most notably, Unicode bugfixes.
Release Notes: Major changes were made to /sys/src/fs, removing some dead code. Some major bugs were fixed. New features were added and the memory limit was increased. See also http://9fans.net/archive/2006/06/471.
Release Notes: Major bugfixes and some new features.