Patrick pretty much summed it up in the accompanying README.  A few notes on 
the specifics for Splack, though:

1.  The kernel-sources package for SPARC was configured for SPARC64.  You'll 
want to reconfigure to build 32-bit kernels, libraries, headesrs, etc.

2.  If you're on a sun4u, be absolutely sure you're in a sparc64 environment 
before you start.  You may want to do a "sparc64 bash" just to make sure.

3.  I'm not building speakup kernels just yet.  It's probably reasonably 
simple, but I'd still rather spend the time coaxing other software to work.  
If someone wants to make a go at it, be my guest.

4.  Anything I'm forgetting?


-- Jason