Status and future of 3rd party ABI compatibility layer

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

Hi all,
there is a lot of code in sys/compat and changes in the kernel API tend
to require changes in this code too. I would like to know which
emulations are actually in use, what the status of emulation is (both in
terms of stability and feature set) and based on that, whether some of
them shouldn't rest in the Attic.

As far as I can tell we have emulation code for:

Darwin (no GUI, doesn't to have been updated in the last 5 years)

FreeBSD (does it even handle FreeBSD 4?)

IRIX

Linux

OSF1

SunOS/Solaris

SVR3

SVR4

Ultrix

Windows/PECOFF (hasn't this been considered dead quite a while ago?)

I don't think we need to discuss keeping Linux. I also don't count NDIS
or NetBSD32 in this area. For the rest, I would find the following
information highly useful to evaluate the maintainance cost and ensure
future support:

(1) Can the emulation run real world application and which? 

(2) If the emulation is considered experimental only:
What progress has been made in the recent time frame (e.g. this decade)
on getting it to a useful and stable state? Is this likely to change?

(3) How can this emulation be tested? Where can reference binaries be
obtained? Has someone done the work to integrate them with ATF or other
scripted test frame works?

(4) Is the emulation in use?

Joerg