Update:  After trying those tools and looking around, I think I've found the right path. 

I'm starting with a whole bunch of code that involves text and images and vector lines, which I wrote up in a private 'language' for a Windows-based courseware engine that I also wrote.  The whole bunch of code needs to be converted into HTML5 so it can be run by platform-independent commercial courseware engines like Moodle.

A few lines of my code:

=============================

ITEM LABEL TERMSULC
 LOC 89 210
 BLINK
 LINECOLOR 3
 LINEWIDTH 5
 SHAPE -43 25 L
 SHAPE -12 18 L
 SHAPE 15 9 L
 SHAPE 34 30 L
 SHAPE 101 189 M
 @Terminal sulcus
}
ITEM LABEL FORCEC
 LOC 114 190
 BLINK
 LINECOLOR 7
 LINEWIDTH 7
 SHAPE -3 19 L
 SHAPE 93 205 M
 @Foramen cecum

}

HTML5 has two different graphics systems: Canvas and SVG.  After a quick look, it's obvious that SVG is what I need.  It has all the same vector commands in a different format.

Randomly picked piece of SVG:

==========================

  <g
     transform="translate(600,150)"
     id="SecondHand">
    <g
       id="RotSecondHand">
      <path
         d="M 0,-82.5 L -2.5,-75 L -4.71875,-8.8125 C -7.85655,-7.12467 -10,-3.81029 -10,0 C -10,3.9979 -7.64307,7.43129 -4.25,9.03125 L -2.5,30 L 2.5,30 L 4.25,9.03125 C 7.64307,7.43129 10,3.9979 10,0 C 10,-3.81029 7.85655,-7.12467 4.71875,-8.8125 L 2.5,-75 L 0,-82.5 z M 0,-2.5 C 1.38,-2.5 2.5,-1.38 2.5,0 C 2.5,1.38 1.38,2.5 0,2.5 C -1.38,2.5 -2.5,1.38 -2.5,0 C -2.5,-1.38 -1.38,-2.5 0,-2.5 z "
         style="opacity:1;fill:#800000;stroke:black"
         id="SecondHandPath" />
   
 
==================================

Same underlying commands, different format.

After choosing SVG, I looked around and found Inkscape, which is pretty clearly the best free tool for building SVG from scratch or from existing images and lines.

http://inkscape.org/

I may use Inkscape directly for the whole conversion, or I may use it for some trial conversions until I understand the 'mapping', and then write a mass converter in Python.   Most likely the latter.

=====================================

Thanks again for the suggestions!  They helped to guide me in the right direction.

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