As of a few days ago, BSDI has released their DOS emulator (`doscmd')
for free redistribution.  I've ported it to NetBSD, and fixed a few
bugs (both in it and in our VM86 support).

There are some caveats to doscmd, as compared to dosemu:
* It doesn't (yet) support EMS, XMS, or DPMI.
* It doesn't (yet) boot my copy of DOS 6.

There are also some advantages:
* The implementation is *much* easier to work on.
* The emulation is complete enough that in many cases you don't even
need to run DOS itself; you can simply boot the application.
* It integrates better into the UN*X environment.  e.g.  Text-only
applications like PKZIP and LHA don't need to take over the window;
they simply output to stdout like you would expect.

Today's results have been very encouraging.  I think with a bit more
effort it can be a fairly solid alternative to dosemu.

Anyone interested in a very preliminary copy of the code should
contact me privately.