TechnologyTrees

This page is a huge mess. It's also so flagrant. But... I need this information laid out...

FreeCiv
FreeCiv, as of version 2.3.0, has a very dense and complex tech tree. Lacking the observational aids such as eras to describe things, I'm going to merely list these top-to-bottom, left-to-right, in sets.
 * Warrior Code
 * Bronze Working
 * Alphabet
 * Ceremonial Burial
 * Masonry
 * Horseback Riding
 * Pottery


 * Iron Working
 * Writing
 * Code of Laws
 * Currency
 * Mysticism
 * Mathematics
 * Map Making
 * The Wheel
 * Polytheism


 * Literacy
 * Trade
 * Monarchy
 * Construction
 * Astronomy
 * Seafaring


 * The Republic
 * Philosophy
 * Bridge Building
 * Feudalism
 * Engineering
 * Navigation


 * Banking
 * Invention
 * Physics
 * Medicine
 * University
 * Chivalry
 * Monotheism


 * Democracy
 * Economics
 * Magnetism
 * Gunpowder
 * Steam Engine
 * Chemistry
 * Sanitation
 * Theory of Gravity
 * Theology


 * Explosives
 * Railroad
 * Metallurgy
 * Leadership
 * Atomic Theory


 * Industrialization
 * Electricity
 * Cosncription


 * Corporation
 * Steel
 * Communism
 * Refrigeration
 * Tactics


 * Genetic Engineering
 * Espionage
 * Electronics
 * Machine Tools
 * Refining
 * Guerilla Warfare
 * Amphibious Warfare


 * Miniaturization
 * Combustion


 * Automobile
 * Flight


 * Mass Production
 * Radio
 * Mobile Warfare


 * Recycling
 * Computers
 * Labor Union
 * Nuclear Fission
 * Advanced Flight


 * Rocketry
 * Nuclear Power
 * Robotics
 * Combined Arms


 * Space Flight
 * Laser


 * Environmentalism
 * Plastics
 * Superconductors


 * Fusion Power
 * Stealth

Civ4
Civilization 4 has had a lot of balance and gameplay observations taken into consideration, and is also most familiar to the inspirations of this game imitation. The eras are still undefined.


 * Fishing
 * The Wheel
 * Agriculture
 * Hunting
 * Mysticism
 * Mining


 * Sailing
 * Pottery
 * Animal Husbandry
 * Archery
 * Meditation
 * Polytheism
 * Masonry


 * Horseback Riding
 * Priesthood
 * Monotheism
 * Bronze Working


 * Writing
 * Metal Casting
 * Iron Working


 * Aesthetics
 * Mathematics
 * Alphabet
 * Monarchy
 * Compass


 * Literature
 * Calendar
 * Construction
 * Currency
 * Machinery


 * Drama
 * Engineering
 * Code of Laws
 * Feudalism
 * Optics


 * Music
 * Philosophy
 * Civil Service
 * Theology


 * Divine Right
 * Paper
 * Guilds


 * Nationalism
 * Printing Press
 * Education
 * Banking


 * Constitution
 * Military Tradition
 * Replaceable Parts
 * Liberalism
 * Economics
 * Gunpowder


 * Democracy
 * Rifling
 * Astronomy
 * Corporation
 * Chemistry


 * Steam Power
 * Scientific Method
 * Military Science
 * Steel


 * Assembly Line
 * Communism
 * Physics
 * Biology
 * Railroad


 * Flight
 * Artillery
 * Fascism
 * Electricity
 * Medicine
 * Combustion


 * Rocketry
 * Industrialism
 * Fission
 * Radio
 * Refrigeration


 * Satellites
 * Plastics
 * Mass Media
 * Computers


 * Advanced Flight
 * Laser
 * Composites
 * Ecology
 * Superconductors


 * Stealth
 * Fiber Optics
 * Robotics
 * Genetics


 * Fusion
 * Future Tech

Civ5
Civilization 5 gave us the best described and observed tech tree, but I think it takes liberties that violate the flow of most of history. However, it divides the tech trees into eras, which gives me something to work with.

Ancient Era

 * Agriculture


 * Pottery
 * Animal Husbandry
 * Archery
 * Mining


 * Sailing
 * Calendar
 * Writing
 * Trapping
 * The Wheel
 * Masonry
 * Bronze Working

Classical Era

 * Optics
 * Philosophy
 * Horseback Riding
 * Mathematics
 * Construction
 * Iron Working

Medieval Era

 * Compass
 * Theology
 * Civil Service
 * Currency
 * Engineering
 * Metal Casting


 * Education
 * Chivalry
 * Machinery
 * Physics
 * Steel

Renaissance Era

 * Astronomy
 * Acoustics
 * Banking
 * Printing Press
 * Gunpowder


 * Navigation
 * Economics
 * Chemistry
 * Metallurgy


 * Archaeology
 * Scientific Theory
 * Military Science
 * Fertilizer
 * Rifling

Industrial Era

 * Biology
 * Steam Power
 * Dynamite


 * Electricity
 * Replaceable Parts
 * Railroad


 * Refrigeration
 * Telegraph
 * Radio
 * Flight
 * Combustion

Modern Era

 * Plastics
 * Penicillin
 * Electronics
 * Mass Media
 * Radar
 * Atomic Theory


 * Ecology
 * Computers
 * Rocketry
 * Lasers
 * Nuclear Fission


 * Globalization
 * Robotics
 * Satellites
 * Stealth
 * Advanced Ballistics

Future Era

 * Particle Physics
 * Nanotechnology
 * Nuclear Fusion
 * Future Tech