As someone that loves to dig into source code to see how things are done...<p>Solaris source is the state-of-the-art. If there&#x27;s a &quot;beautiful&quot; kernel, Solaris is definitely the one. QNX also is one very well made kernel(its like a OS created by a zen master).<p>It&#x27;s a pity that sun took so long to open the source of Solaris, or else i could be typing this from a solaris kernel, instead of Linux.