Why are 2D vector graphics so much harder than 3D?
&gt;This new printer was based on a small, stack-based Turing-complete language called Forth, and they named it… the Interpress!<p>Xerox&#x27;s laser printers were never &quot;based on Forth&quot;. 
JAM and Interpress were only conceptually related to Forth, in that they used postfix semantics.<p>That&#x27;s like saying that because Java byte code uses a stack, your Android phone is based on Forth. It&#x27;s not. Stack based architectures (like the Burroughs B5500 and B6500, developed in 1962, which directly inspired Design System =&gt; JAM =&gt; Interpress =&gt; PostScript) have been around a lot longer than Forth (developed in 1970), and simply using a stack doesn&#x27;t make a language Forth.<p>Here&#x27;s a much more accurate and detailed historical account of the history of Interpress, written by Brian Reid:<p><a href="https:&#x2F;&#x2F;groups.google.com&#x2F;forum&#x2F;#!topic&#x2F;fa.laser-lovers&#x2F;H3us4h8S3Kk" rel="nofollow">https:&#x2F;&#x2F;groups.google.com&#x2F;forum&#x2F;#!topic&#x2F;fa.laser-lovers&#x2F;H3us...</a><p>Gaffney came to E&amp;S from graduate school at the University of
Illinois, where he had used the Burroughs B5500 and B6500 computers.
Their stack-oriented architectures made a big impression on him. He
combined the execution semantics of the Burroughs machines with the
evolving Evans and Sutherland imaging models, to produce the Design
System. Like all successful software systems, the Design System slowly
evolved as it was used, and many people contributed to that evolution.<p>John Warnock joined Xerox PARC in 1978 to work for Chuck Geschke.
There he teamed up with Martin Newell in producing an interpreted
graphics system called JAM. &quot;JAM&quot; stands for &quot;John And Martin&quot;. JAM
had the same postfix execution semantics as Gaffney&#x27;s Design System,
and was based on the Evans and Sutherland imaging model, but
augmented the E&amp;S imaging model by providing a much more extensive
set of graphics primitives.  Like the later versions of the Design
System, JAM was &quot;token based&quot; rather than &quot;command line based&quot;, which
means that the JAM interpreter reads a stream of input tokens and
processes each token completely before moving to the next. Newell and
Warnock implemented JAM on various Xerox workstations; by 1981 JAM
was available at Stanford on the Xerox Alto computers, where I first
saw it.