Just a Reference/Hint

[martinvahi]

You may want to get acquainted with the
Antikernel project,
which is not my project, but that of Andrew_Zonenberg's.

Another project that You may want to take a look
is the open source FPGA development tools suite by the
IceStorm project author, the Clifford Wolf.

The HelenOS and the Niklaus Wirth's
Oberon open source study materials project, which has a fan site,
are not for production use, fail to meet many practical requirements of
production use, but they are very inspirational and demonstrate the possibility of
some interesting "extremes".