In 2004, I had an idea to write a series of TechNotes to help developers obtain a basic understanding of principles in computational geometry. I also decided to start a blog and authored a small AS library to go along with the material. It seems that so many people turn to high-priced books for information and I simply wanted quality material to be available for free.
The Singularity library began in AS2 and was eventually ported to AS3. Although never intended for commercial use, I now have dozens of requests for use of the library in commercial applications. One recent application was in a set of new features for a product called Scrutinizer ™.
The upcoming release will use the arc-length parameterized quad. Bezier to draw dashed arcs.
While the Singularity package is no longer available (its capability ported to and expanded upon in Degrafa), I’m glad that a lot of people learned something new and applied it to actual applications.
The Algorithmist 
I never got into Degrafa, seemed so much drawing oriented (when I usually only need the pure splines). I look at it’s docs now, but it mentions “.. is optimized for drawing in the Degrafa command stack” quite a lot, while Singularity is just geom. Does Degrafa work well for only abstract geometry?
Degrafa is primarily for drawing, but there are many geom. utils that can be used standalone. I went through a lot of work to make sure the spline architecture was driven in a way that decoupled the spline computations from the Degrafa drawing architecture. So, those can be used ‘as is’ outside Degrafa.