Pretty awesome tools:
* Writing (and related tools like paper, codices, etc.), and language in general
* The city
* Mathematical notation (even though some parts are kind of dumb and could use updating)
* Logarithms (and slide rules)
* Calculus
* Geometric algebra
* Chebyshev polynomials
* The discrete Fourier transform
* Maxwell’s equation(s)
* Glass windows
* Refrigeration
* The court system
* Public libraries
* The post office
* Representative democracy
* Non-violent civil disobedience
* Open source
* Lambda calculus
* PEG grammars / packrat parsers
* The Python programming language
* TCP/IP, Email, IRC, HTTP, and so on
* The Munsell color system and its derivatives
* A shower with hot water
* The washing machine
* Chopsticks
* Photoshop
* Incandescent light bulbs (and the electric grid generally)
* The Socratic method
* The vacuum flask / thermos
* Condoms and other birth control
* Diapers
* Blankets
* Flexible shoes (e.g. shoes with canvas soles, thin leather mocassins, Vibram five-finger shoes)
* The Aeropress
* Wikipedia
* Rope
* Binoculars