Also, I'm ignorant of how MCL deals with networking. Maybe they do some
wacky stuff above socket, listen, accept, connect, read/write and select.
But it's hard to fathom what. Most of the Lisp socket implementations seem
to expose that high level aspect of the API. Most don't go down into the
deep nuances of TCP and IP that the raw, low level APIs of the Berkley
Sockets, but most applications don't need that level of detail. Maybe your's
does.

Most of the "threading" implementations seem very similar to the CLIM model
as well, but again, I don't know anything about MCL. Of course some of those
implementations differ as to whether they use native threads or not. I think
even Franz's implementations vary across platforms, tho the API is the same.

But, basically, you're saying that the level of platform dependence of your
Lisp code is so ingrained, that it's not even worth pursuing to port it to
your Linux machine. Best throw it all out and start new on the Linux box.
That it is not worth implementing the MCL specific calls on your Linux Lisp
to port your code. It is simply too difficult, and the code isn't worth it.

Does it affect casual porting of the code? Sure it does. But even conforming
implementations have issues porting code, even if they implement the same
APIs. Look at the difficulty of porting Unix apps to Mac OS X. Porting those
apps to Mac OS 9-- were Just Too Hard. But now that there is "more unix",
applications and code can more easily be bent to work on OS X, so porting is
worthwhile vs tossing it all away and starting anew.

But if  you were willing to post your code, perhaps someone else would find
the value of the code worth the effort to actually port it, then again,
maybe it simply relies too much on the MCL implementation.

We we're mostly talking sockets and threads here I thought.

Regards,