I'm too lazy to sort out the differences between previous and current log. So that's the current one:
Version 1.5.5 (March, 2015)
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Added:
* Added number of turns each pact has been in effect to the diplomacy screen.
* Added custom mouse cursor graphic.
* Added video setting for choosing the title screen.
* Added support for unicode characters up to and including the Cyrillic script (0x4FF), allowing those characters to work correctly with the Plain (DejaVu Sans) font as well as any other custom unicode font that has the corresponding glyphs.
* Added AI ability to dynamically alter their tax-rate.
* Added ability to raze cities to the AI if their morale gets too bad.
* Added two sets of new icons for farmers, miners, workers and scientists that gain higher yields than normal.
* Added option in Pandora.xml to switch between the two sets of new icons.
* Added a mechanism for the AI to check how usefull a war will be and make its decision to go to war dependand on that.
* Added code that allows the AI to flank targets.
* Added AI ability to dynamically evaluate whether it should commit to a rush or go heavy on economy and science.
* Added better support for teams in AI's diplomatic behaviour.
* Added a new mechanism for the AI to determine whether it should build units or economy. It prevents overcommiting on either by tieing them together with a dynamic percentage-value.
Changed:
* Moved Planetary Market to one subtier earlier in the research tree.
* Improved mouse wheel scrolling of GUI components.
* Made terrain-colors on the minimap much darker to make it easier to tell it apart from cities and units.
* AI now is less aggressive about dealing with aliens.
* AI now chooses technologies to research in a similar fashion of how experienced players choose technologies.
* AI now will, in average, commit more scientists to research.
* AI now considers pollution when assigning population to jobs.
* AI now will expand much slower and focus more on improving its existing cities instead.
* AI now considers quality more important than quantity when it comes to building units.
* AI will now prefer late-game-devices over early-game-devices.
* AI now has an emergency behaviour to resolve economical crisis.
* Reworked how AI determines it's tile-improvements. It should now be much closer to what an experienced player chooses.
* AI will be more careful with its units when exploring.
* AI now will heal wounded units before sending them to attack.
* AI now considers more sophisticated criteria when choosing locations to expand to.
* AI now considers more sophisticated criteria when choosing tiles to expand it's existing cities borders to.
* AI no longer builds new formers as long as enemies are within the area of their city.
* Improved AI behavior when it comes to avoiding the loss of formers.
* AI now can perform several diplomatic actions within one turn.
* AI now will gradually lower their diplomatic relations to whoever is closest to victory.
* AI will no longer grant you gifts all the time just because they like you.
* AI players are now more difficult to convince to declare war on others.
* AI now will prioritize devices that best fit the unit-type.
* AI now will consider the tier of unit-components except of the device when evaluating which unit to build.
* AI now can and will use fungus once it has the two advancements boosting its yield.
* AI will now allocated more minerals into boosting its newly found cities.
* AI will now lower their standing to someone capturing a city depending on that cities importance for its previous owner.
* AI now takes device and unit-type into consideration, when deciding which units to use as defenders.
* AI no longer considers distance when picking defenders for its cities.
* AI no longer voluntarily gifts away its credits.
* AI will now use bombardment and nukes primarily to kill transports and disrupt healing in besieged cities.
* AI will now be much more carefull about where to use blackholes.
* AI will now rather save a WMD for better use than to risk overnuking a target.
* Depending on their aggression-level AIs now may consider making more units as a means of expansion rather than building colonizers.
* AI will now rather pillage tile-improvements instead of retreating if it considers the defenses of a city too strong.
* Improved AI behavior when confronted with long-range-units.
* AI will now be more careful about where to colonize.
* AI will now keep units inside their cities if they are not needed otherwise.
* AI will now consider WMD-buildings more valuable.
* AI now is much more likely to build naval units in coastal cities.
* AI will no longer value research once it has enough science for a research-victory.
* AI will now allocate its population differently when it is at war or when it is preparing for war.
* AI will no longer sign sciene treaties with those who are above average in research.
* Moves of Earthling-factions are now prioritized over moves of alien-factions.
* AI will now prioritize enemy units in their territory as more important target.
* Allowed AI to use all unused ships for exploring.
* AI now will use a certain amount of artillery-type units in their offenses.
* AI will use mineral-sources with less than two minerals only if there's almost no other minerals available.
* AI will no longer build watercraft when it is at war with someone who only has cities with no access to water.
* When playing as Togra University the AI will make use of Zak0r's upgrade-strategy.
* AI decision when to make peace now is more in line with its decison when to declare war.
* When refitting the AI will now stick to the same weapon type to stay cost-efficient.
* AI will now always prioritize refitting their units over purchasing other stuff.
* If the AI is at war with someone and doesn't know any cities of that someone but it has seen the border, it'll prioritize exploring there.
* Made sure that AI always uses their artillery-units before its other units.
* When at war with another faction, the AI will be much less likely to attack native wildlife.
* AI now will rather upgrade its formers to amphibious than using harvest.
* AI now is more sensitive about wheter it should perform a rush or prepare to defend against one.
* AI now will try to avoid getting its Transports spotted by its enemies.
* AI now will value forests more for fighting pollution before it has Pandora Construction.
* AI now will prefer tiles that are most suitable for their units when approaching an enemy city.
* AI will no longer retreat heavily injued units to a city under the effect of an ion-storm.
* Increased maximum amount of playable factions via advanced setup in a game from 9 to 13. Only makes sense with a mod that adds new factions.
* Improved AI behaviour in city-defense.
Fixed:
* Fixed a crash that could occur when loading a save game in a specific state.
* Fixed operations not replacing durations when deployed on territories.
* Fixed Scites and Carcharodons turning aggressive before Xenomorphs.
* Fixed water suburbs and water purifiers costing 2 credits instead of 3.
* Fixed Fungus Mutagenesis and Fungal Hormones not providing bonuses for water fungus.
* Fixed army panel sometimes showing units that are no longer in the territory.
* Fixed mouse wheel sometimes not scrolling drop lists.
* Fixed errors in German translation-files.
* Fixed AI not building advancements unlocked by killing sea-monsters.
* Fixed a rare case where the AI would waste some of it's mineral income each turn.
* Fixed an issue where paying tribute was considered the same as denying to pay.
* Fixed AI ships acquiring targets near unreachable inland-lakes.
* Fixed AI upgrading units into options that aren't even actually better.
* Fixed an exploit where you could reduce the amount of credits an AI asks for during negotiations by spending them before stating you are willing to pay.
* Fixed AI ignoring how you react to a tribute-offer. Standing will now properly change.
* Fixed a bug that prevented AI from realizing it cannot heal in water-fungus.
* Fixed game-pace not affecting the duration of temporary tile-modifications like the ion-storm cast by the Messari.
* Fixed an issue where AI units could get stuck when they targeted something they could not see.
* Fixed AI not using as many units for defending as it should.
* Fixed AI Artillery and Sniper-units not always attacking targets when they should.
* Fixed a bug that under certain circumstances led to miscalculation on city-growth when using the growth-project.
* Fixed AI not caring about their new cities for the turn they are founded.
* Fixed a bug that swallowed the majority of diplomacy-messages sent to the player by the AI.
* Fixed Ambassadors leeching from pacts not actually being added to their income.
* Fixed an issue causing AI land-units to try and pillage improvements inside lakes.
And here is a screenshot that demonstrates the current capabilities of the AI:
Easy-level, non-cheating, AI winning the game in turn 211. That improves the old record by more than 40 additional turns.