Learning Sanskrit
पाणिनीयधातुपाठः – https://ashtadhyayi.com/dhatu/
अष्टाध्यायीसूत्रपाठः – https://ashtadhyayi.com/sutraani/
Sanskrit Dictionary
https://dsal.uchicago.edu/dictionaries/apte/
http://www.andhrabharati.com/dictionary/sanskrit/index.php
Upanishads
https://www.upanishads.iitk.ac.in/
https://advaitasharada.sringeri.net/
https://sanskritdocuments.org/sanskrit/upanishhat/
Ramayan
https://www.valmiki.iitk.ac.in/
Ramcharitmanas
https://www.ramcharitmanas.iitk.ac.in/
Work of Adi Sankara
https://www.sankara.iitk.ac.in/