FreeCol is an open source project that aims to provide a free Colonization clone. FreeCol is released under the GPL.
Quote:
We have released FreeCol 0.10.0-alpha. The new release is not yet stable, but fixes many old bugs and adds numerous new features. It should be able to read all 0.9.x savegames.
Changes to increase Colonization compatibility
secondary production no longer benefits from plowing
horse production consumes less food
treasure from destroyed native settlements is now closer to the original
choice of cargo to loot when winning a naval battle
clearing a tile will sometimes uncover a resource
Spanish national advantage now includes attack bonus against natives
Other user-visible changes
new theme
selectable rules
custom difficulty
new goods type "grain"
"clear forest" accelerator is now "C", "center" is now "Ctrl-C"
display the last sale price of goods at native settlements
many bugs fixed, some quite old:-)
Other changes
better client-server communication, reduces synchronization issues
cleaned up external dependencies (cortado, etc.)
fixed sound for some (most/all?) users
localization files are now encoded as UTF-8