Experimental OS

Can anybody suggest any experimental, easy to understand operating system written in a high level language on which I can do some interesting stuff as a learning exper开发者_StackOverflow社区ience. There are some OS like MikeOS, TomOS etc but these are written in assembly languages.

Basically, I want an OS which has driver support for power management but should not be very large.

House, written in Haskell ontop of the H interface and GHC runtime system. Alternatively, consider a paravirtual machine that runs on Xen like mini-os (written in C, lives in the Xen repository) or HaLVM (a Haskell cross compiler to the Xen ABI).

Moving away from the Xen / Haskell realm, you could look at Haiku - a reimplementation of BeOS in C++.

While I haven't looked at the code myself, MINIX has a reputation as an easy-to-understand educational operating system. You'll have to see for yourself whether it has power management support, though the web size does say MINIX 3 is targeted at embedded systems, so I'd say your chances are good.