cryptography
1. ./stuff/manualdf.html - manual diffie-hellman
2. ./stuff/base64.html - base64
electronics
1. ./stuff/baud.html - baud rate calculator
physics
1. ./stuff/light.html - everything about light
2. ./stuff/tm.html - timezone corrector
data theory?
1. ./stuff/shannon.html - shannon's entropy
2. ./stuff/popdyn.html - population dynamics