Most original Siddhar works are over 500 years old and fall into the . However, the digital scans and modern interpretations (with commentary) are copyrighted.

: An excellent government-backed resource for digitized ancient manuscripts and rare books. You can find key texts like Siddhar Aruvai Maruthuvam (Surgical Medicine) and general Siddha Medicine manuals TKN Siddha : Provides a categorized list of Tamil Siddha Medicine books

The word Siddhar (or Cittar ) refers to a "perfected individual" who has attained , or supernatural spiritual powers. Historically, the tradition identifies 18 Main Siddhars (Pathinen Siddhargal), though hundreds of others have contributed to the corpus of work.

, are the central figures of this tradition. Their works, collectively known as or Siddhar Gnana Kovai