Daremberg-Saglio
A PDF-version of the Dictionnaire des antiquités grecques et romaines has been put on-line by the Université de Toulouse.
http://dagr.univ-tlse2.fr/sdx/dagr/index.xsp.
De Ruggiero
An on-line version of De Ruggiero's Dizionario epigrafico di antichità Romane
A-B: http://archive.org/details/dizionarioepigr00rugggoog.
C: http://archive.org/stream/dizionarioepigr01rugggoog#page/n7/mode/2up
Pauly Wissowa
Several digitalised version of this Mother of all Encyclopaedia's circulate on line:
http://de.wikisource.org/wiki/Paulys_Realencyclopädie_der_classischen_Altertumswissenschaft
http://archive.org/search.php?query=Pauly-Wissowa%20AND%20mediatype%3Atexts