Plan 9 and its successor/spin-off Inferno are both in active development. Main difference: Plan 9 has a virtual memory system and Inferno just uses a fla

Plan 9 and its successor/spin-off Inferno are both in active development. Main difference: Plan 9 has a virtual memory system and Inferno just uses a flat address space. [...] User space tends to be completely different as Inferno's user space is entirely within the virtual machine. Plan 9 can run [...] generic binaries. -- http://www.osnews.com/thread?249033 http://www.osnews.com/thread?249033 Inferno repo: https://code.google.com/p/inferno-os/source/list https://code.google.com/p/inferno-os/source/list (latest commit May 25, 2014); http://en.wikipedia.org/wiki/Inferno_(operating_system) http://en.wikipedia.org/wiki/Inferno_(operating_system) Plan 9 repo: http://plan9.bell-labs.com/sources/ http://plan9.bell-labs.com/sources/ (latest commit May 26, 2014); http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs