1. Unix pipes are 1 dimensional<p>grep ”^#” dat1 | foobar &gt; dat2<p>whereas the key thing about this idea is that real pipes can be multidimensional<p>grep ”^#” dat1 | foobar<p>|                  |<p>|                  |
snafu | stitch &gt; dat2<p>2. This system treats &quot;&gt;&quot; as a program in itself and verifies a &quot;program descriptor&quot; before it trashes the next one in the pipe<p>3. Unix pipes give you the error code of the first stopped component in the pipeline whereas in this model you can hook up instrumentation&#x2F;statistics to any stage of the pipe