The greatest example of penmanship among hackers has to be Edsger W. Dijkstra.

  Dijkstra was well known for his habit of carefully composing manuscripts with his fountain pen. The manuscripts are called EWDs, since Dijkstra numbered them with EWD, his initials, as a prefix.

Dijkstra maintained a consistent beautiful handwriting, and was ambidextrous. These EWDs inspired me to pick up a fountain pen for my own writing.

PDFs of his EWDs can be found at https://www.cs.utexas.edu/users/EWD/

An example EWD: https://www.cs.utexas.edu/users/EWD/ewd13xx/EWD1300.PDF