🚀 go-pugleaf

gnuchess itself doesn't contain any code to interface to the ICS.  The
few small sections of code that are marked #ifdef CLIENT contain code
that is slightly changed when using gnuchess with a *separate program*
that interfaces with ICS.  (I suspect most or all of those ifdefs will
go away in the future, by the way.)

There are currently several programs that interface gnuchess with ICS.
Mike McGann, the primary developer on gnuchess, has one that he uses
for the "gnufour" player.  It's based on xics.  I have a modified
version of xboard that I use for the "Zippy" player.  There are also
several other versions of gnuchess on ICS, such as MaxII and Hill.  I
haven't seen the code they use to interface to ICS, but you could ask
their proprietors on ICS (egg and dima respectively).

I'm in the process of cleaning up the modified xboard, and I expect
Mike may adopt it in the future and throw away his modified xics.  I'd
be willing to release it selectively to other interested people at
that time.  Alternatively, I could send you a copy now if you're in a
hurry, but it has some rough edges, and it will need some small
modifications when gnuchess 4.0 pl63 comes out.

	--Tim