Kerbal Space Program .25 Economic Boom has finally come.
This update brings several new things to the game from Spaceplane+ to the new Administration Facility.
There are really too many additions to this update to list them all here, your best bet would be to check out their FAQ page here.
A Few of the highlights for this update are:
Spaceplane+: More spaceplane parts, plus more parts for rockets as well. And best of all, cargo bays.
Administration Building: Players will be able to select and activate Strategies. This is a new player mechanic will affect aspects of the game for Carrier Mode.
In Depth Difficulty System: Players will be able to better customize how hard core they want their game to be.
Upgraded FX on Explosions: Kind of self explanitory here.
Destructible Building: Watch those falling parts, a damaged part of the KSP facility can be rather costly to fix/replace.
64Bit Issues
There is a issue with the 64Bit build, they are working on it, but it can be a bit unstable.
Have fun