which didn't detect the MacTCP emulation in Owen's Open Transport. [originally from svn r2703]
[originally from svn r2573]
it does compile and link. [originally from svn r2547]
we can have runtime switching between MacTCP and OpenTransport, and so that we can cope if there's no TCP/IP stack available at all (albeit with very little functionality at present). [originally from svn r2546]