Oberon V4
Oberon V4 for Linux and sources for different Oberon V4 implementation
Here you can find both an Oberon V4 system for Linux (x86) and a collection of Oberon V4 sources for various other platforms.
Oberon V4 was implemented at ETH Zurich for several platforms. Binaries can be found on their server[1] and on the one of the University of Linz[2] where Mössenböck's group did further development after he left ETH and the Group at ETH concentrated on System 3.