Proto-Indo-European Lexicon is the generative etymological dictionary of Indo-European languages.
The current version, PIE Lexicon Pilot 1.1, presents digitally generated data of hundred most ancient Indo-European languages with three hundred new etymologies for Old Anatolian languages, Hitttite, Palaic, Cuneiform Luwian and Hieroglyphic Luwian, arranged under two hundred Indo-European roots.
The correspondences contain data of all fourteen sub-branches of the Indo-European languages, Albanian, Anatolian, Armenian, Baltic, Celtic, Germanic, Greek, Indo-Aryan, Iranian, Italic, Old Balkan (Satem), Old Balkan (Centum), Slavic and Tocharian.
In particular, problematic etymologies of Anatolian languages have been chosen, and in the absence of other criteria the choice of examples is random. However, as all the oldest forms of the languages are represented, the ancient languages still absent are supplemented in the near future.
More information on the lexicon: http://pielexicon.hum.helsinki.fi/