<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;RTML" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;RTML</a><p>I&#x27;ve never used the thing, so I&#x27;m just going off what I&#x27;ve found.<p>According to Graham, in 2003:<p>&gt; (a) The reason they rewrote it was entirely that the 
current engineers didn&#x27;t understand Lisp and were too
afraid to learn it.<p>&gt; (b) The resulting program is a new world&#x27;s record case
of Greenspun&#x27;s Tenth Rule.  The Yahoo Store Editor called
compile at runtime on s-expressions made on the fly.
To translate this into C++ they literally had to write a
Lisp interpreter.<p><a href="http:&#x2F;&#x2F;people.csail.mit.edu&#x2F;gregs&#x2F;ll1-discuss-archive-html&#x2F;msg02367.html" rel="nofollow">http:&#x2F;&#x2F;people.csail.mit.edu&#x2F;gregs&#x2F;ll1-discuss-archive-html&#x2F;m...</a><p>So granted, &quot;Lisp-based&quot; would mean &quot;based on a custom ad hoc partial reimplementation of Lisp.&quot;