It&#x27;s not a very detailed explanation but the write-up is here: <a href="http:&#x2F;&#x2F;techn.ology.net&#x2F;visualize-move-protection-and-threat-status-in-chess&#x2F;" rel="nofollow">http:&#x2F;&#x2F;techn.ology.net&#x2F;visualize-move-protection-and-threat-...</a><p>It&#x27;s written as a server program in Perl, but it&#x27;s relatively easy to install and run on your own computer:<p>&gt; git clone <a href="https:&#x2F;&#x2F;github.com&#x2F;ology&#x2F;Chess-Inspector.git" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ology&#x2F;Chess-Inspector.git</a><p>&gt; cd Chess-Inspector<p>&gt; perl Makefile.PL<p>&gt; make<p>&gt; sudo make install<p>&gt; perl bin&#x2F;app.pl<p>Then open <a href="http:&#x2F;&#x2F;localhost:3000" rel="nofollow">http:&#x2F;&#x2F;localhost:3000</a> in your web browser. Voila!