From the website:
The Collected Tantras of the Ancients (rnying ma rgyud ’bum) is a canon of esoteric scriptures revered by the Nyingma (rnying ma) or “Ancient” school of Tibetan Buddhism. The collection is unique in three important respects. First, its Tibetan translations are the only extant version of many Indian Buddhist texts otherwise unavailable. Second, the canon reflects a syncretic assimilation of literary influences from Buddhist traditions across India, China and Central Asia. Finally, The Collected Tantras represent an important body of indigenous Tibetan works that reflect original Buddhist literary traditions, including the Great Perfection (rdzogs chen), arguably the last great philosophical development of South and Central Asian Buddhism. There is recent consensus among a small but growing corps of modern scholars that this corpus contains materials vital for understanding Tibetan Buddhism from the eighth to fourteenth centuries and for reconstructing Buddhism's history in India and Central Asia between the eighth and tenth centuries. This latter period is one for which our knowledge from other sources is particularly fragmentary. Thus, The Collected Tantras of the Ancients comprises documents essential for research into ritual, contemplation, philosophy and literature. This section of the digital library contains information and scholarship on The Collected Tantras, including a comprehensive catalog of the texts contained in the corpus as well as scanned folio images for some editions.
The scanned images of the mTshams brag, gTing skyes and Bai ro editions of the rNying ma rgyud ’bum are all courtesy of the Tibetan Buddhist Resource Center (www.tbrc.org). If you are interested in obtaining personal copies of entire editions on CD, please contact TBRC for ordering information. The accompanying catalog and interface available through THL is not currently available for offline use. However, we plan to make it available at some point in the future.