We created the language because of our frustration with how tedious and time consuming it can be to create complex vector drawings. Why sit in front of a screen for hours clicking and dragging with a mouse when you can spend a few minutes thinking about your drawing, solving a few geometry and trigonometry problems and then writing a simple program that will create the drawing for you? It's less tedious and a lot more fun, plus you get to sharpen your math and programming skills.
The book comes with software that translates a drawing definition in the Nell language into an SVG file. The software is free and open source with a GPL license.