In
Sid Meier's Alpha Centauri (
SMAC), the Planetary Datalinks is a
Secret Project. It may be built at a cost of 270 minerals, on discovery of
Cyberethics (B3). It gives your faction any
Tech known to at least three other factions.
How useful is this? Unless you're playing the Believing faction (orange, Sister Miriam), or playing a high difficulty setting, your research and diplomacy shouldn't be so lagged as to make this Project as useful as others in its price range. Under the aforementioned conditions, however, it can help keep your faction competitive, and it seems that the leading computer-controlled factions tend not to bother building this Project, so at Transcend level it may be the first Project you get to complete before your rivals. Having a real need for the Planetary Datalinks is an indication that your game isn't going very well.
SMAC's online helps system is styled as "datalinks"; in the story of Planet's colonization the Datalinks are the repository of terrestrial knowledge and culture brought to Planet on the starship Unity. The Planetary Datalinks, then, is analogous to the Library of Alexandria Wonder in the forerunner Civilization: since so much scholarship passes through the base where the Datalinks Project is constructed, presumably the owning faction gains access to the background research that underlies technological advance.
Secret Project animation narrative:
"As the Americans learned so painfully in Earth's final century, free flow of information is the only safeguard against tyranny. The once-chained people whose leaders at last lose their grip on information flow will soon burst with freedom and vitality, but the free nation gradually constricting its grip on public discourse has begun its rapid slide into despotism. Beware of he who would deny you access to information, for in his heart he dreams himself your master."
-- Commissioner Pravin Lal,
"U.N Declaration of Rights"