- A Logic Calculator. Test if an argument is valid or invalid. Generate truth tables. Find counterexamples. etc.
- Definitions from Quine's
*Mathematical Logic*. See how basic mathematical constructs can be reduced to statements about sets and classes. - Possible Worlds Semantics for Second-Order Modal Logic. An unfinished attempt to define logic in terms of possible worlds.
- Probability in Light of Independent Testimony for Mutually Exclusive Possibilities. How to calculate probability from conflicting and corroborating testimony (under certain circumstances).

- Javascript Drum Machine.
- Musical Interval Explorer. Hear arbitrary harmonic intervals and chords in any tuning in your browser.

- Clock with Invented Hexadecimal Digits
- My Blog. Rarely updated. Miscellaneous topics.