MAC layer network access in Unix?

[Jerry Lahti]

SunOS 4.x has the NIT interface which provides access to Ethernet MAC 
frames for user processes.  Do other Unixes have equivalent facilities?
What is the situation in e.g. MIPS RiscOS, Ultrix, HP-UX, AIX? How
about 4.3Bsd-Reno?

Send mail and I will summarize.

Jerry Lahti
Nokia Data Systems Oy, Workgroup Systems/LAN
Domains: jel at tuura.yj.data.nokia.fi