GraphicPane: this project aim to create a pane and plot into it some graphics.
I have the feeling they updated the libraries with Catalina, but it works.  I organized a Raw2DPane which prints on screen and a CartesianFrame:Raw2DPane which implements (guess what) a Cartesian frame. We can draw vectors, points, straight lines and curves. We also graph a cosine. 
Encapsulation is not great, yet. I should try and integrate with GeoSIR.
BTW: in Cubic Bezier the control points are proportional to the tangent vectors (1/3*v).

GeoSIR: this is a project to create a simulator of epidemic based on graphs. One can describe quite a general epidemic model and one model will be run at any node of a geographic graph. Commuters from one node to another can be considered to spread contagion fom one node to another.
1.0.1: The simulator works quite well.
Next I would like to best fit parameters with some algorithm which does not uses derivatives.

Hackberry: I found a tutorial to stop and hack the boot of a raspberry.I bought a raspeberry to try to hack and use it to build a OS according to From Nand to Tetris II.

TagFS: define a filing system for mac based on tags.
The implementation is based on an acyclic graph of tags to describe inheritance.

myMath: math library for mac in Swift 5.1.

myGraph: graph libraries in Swift 5.1.

From Nand to Tetris: Run an OpenLab about that course and design a microprocessor from scratch.

TeX: libraries in plain TeX to deal with furmula numbering, references, ...