If you're a Java 2D programmer, you've surely seen the word "ductus". Probably in a context like this:

at sun.dc.pr.PathStroker.endPath(Native Method)
at sun.dc.pr.Rasterizer.endPath(Rasterizer.java:561)
at sun.java2d.pipe.DuctusRenderer.createShapeRasterizer(DuctusRenderer.java:576)
at sun.java2d.pipe.DuctusShapeRenderer.renderPath(DuctusShapeRenderer.java:57)
at sun.java2d.pipe.DuctusShapeRenderer.draw(DuctusShapeRenderer.java:45)
at sun.java2d.pipe.PixelToShapeConverter.drawLine(PixelToShapeConverter.java:34)
at sun.java2d.SunGraphics2D.drawLine(SunGraphics2D.java:2101)

And you've probably wondered what it meant. What is a "ductus" shape? Is it a concave shape, maybe?

Nothing so interesting. It turns out that I parsed "DuctusRenderer" wrong. It's not a renderer of ductuses; it's Ductus' renderer. Ductus being a company that licensed their rendering technology to Sun.

Boring but true.