Cool Things Made by Others

• 4D Golf
  • A fully four-dimensional golf game. Surprisingly intuitive!
• Quiver
  • Tool for creating commutative diagrams.
  • Exports to LaTeX.
• Penrose Graphical Notation
  • An alternative to tensor index notation.
  • This link may not be optimal; I should find or make a better one.
• Interesting Papers:
  • A General Nullstellensatz for Generalized Spaces
    • If you want to work internally to an arbitrary classifying topos, what axiom scheme should you start with?
  • A Typed, Algebraic Approach to Parsing
    • What if we use parser combinators, but don't throw out all of parsing theory?
  • Sound and Complete Bidirectional Typechecking for Higher-Rank Polymorphism with Existentials and Indexed Types
    • This is basically a complete programming language, with a type system in some ways more powerful than Haskell's, fully specified and proven correct, all in a single paper!
  • Kerr Geodesics in Terms of Weierstrass Elliptic Functions
    • Derivation of trajectories around a spinning black hole. (For the non-spinning case, see Wikipedia.)