There are at least eight different variations of the S’iva Sahasra nAma. One appearing in the Book 13 (Anus’asana Parva) of MahA bhArata is considered as the main version.
One version is contained in Linga purANa while another version in MahAbhArata. Identical names of Siva and Vishnu occurring in the sahasra nAmas have led Adhi Sankara to conclude that both Siva and VishNu are identical and they both are monotheistic GOD.
This conclusion forms the basic concept of Advaitam.
Also other names of Siva were told by Sree Krishna himself to Yudhisthira in the MahA bhAratha. Again Krishna himself recited another version of the Shiva Sahasranama, the 1008 names of Siva in the 17th chapter of AnushAsanaparva of MahA bhAratha.
The list of the different versions:
Linga PurANa (version 1, LP 1.65.54-168)
Linga PurANa (version 2, LP 1.98.27-159)
Siva purANa (4.35.1-131.)
MahA bhAratha – S’Anthi parvan version (12.284.68-180.)
VAyu PurANa (1.30.179-284)
BrahmaNda PurANa (38.1.1-100) i
MahA bhAgavatha Upa purANa (67.1-125)
Rudhra Sahasra Nama 