Prasthānas

The prasthāna-traya is the three-fold path to the highest truth.
  • śruti-prasthāna -- upaniṣads
  • smṛti-prasthāna -- bhagavad gītā
  • yukti-prasthāna -- brahma sūtras

prakaraṇas

Before studying the prasthāna traya proper, seekers traditionally gain a basic grounding in the subject by studying one or more prakaraṇa works. These works are a basic outline of the subject. A new edition of two such works is offered here.
 
Note: The mahesh research institute has published similar editions with 8 and 12 works respectively (prakaraṇāṣṭakam and prakaraṇadvādaśī, both of which are available from the Arsha Vidya Gurukula bookstore)
  • [ link ] prakaraṇāni -- (1) aparokṣānubhūti with vidyāraṇya's ṭīkā, (2) ātma bodha with an unknown ṭīkā. 

The links below are to well-known sanskrit editions of the prasthāna traya (the three-fold path). The are hosted at archive.org. 

gītā (smṛti)

  • [ link ] gītā with the commentaries of śaṁkara, ānandagiri, dhanapati, madhusūdana sarasvatī and others
  • [ link ] gītā with the commentaries of śankarānanda, dhanapati, madhusūdana sarasvatī, daivajña and others
  • [ link ] bhāṣyārka prakāśikā by rāma rāya kavi

upaniṣads (śruti)

The ten primary upaniṣads are the (1) īśa, (2) kena, (3) katha, (4) praśna, (5) muṇḍaka, (6) māṇḍūkya, (7) taittirīya, (8) aitareya, (9) chāndogya and (10) bṛhadāraṇyaka. The publications below are all aligned with śaṁkara's commentary.

simple commentaries:
  • [ link ] 8 upaniśads with the introductory prasāda commentary by swāmī bhāskarānanda 
  • [ link ] 10 upaniśads with the introductory maṇiprabhā commentary by amaradāsa
  • [ link ] kena, katha and muṇḍaka upaniśads with śaṁkara's bhashya and a new bala-bodhinī tīkā
  • [ link ] īśa, kena, katha, muṇḍaka and taittirīya upaniśads with śaṁkara's bhashya and a few footnotes
advanced commentaries (all featuring the śaṁkara's bhashya and ānandagiri's tika)
  • [ link ] 10 upaniṣads with the a plethora of sanskrit footnotes by heads of the Kailasa ashrama
  • [ link ] 8 upaniṣads with additional subcommentaries on the katha, māṇḍūkya and taittirīya upaniṣads
              ( Mahesh research institute reference editions. ) 
  • [ link ] cāndogya upaniśad (Mahesh research institute reference edition) 
audio / video
  • [ link ] Upanishad Ashtadasha: Hindi lectures (youtube) by the Kailasa ashrama
  • [ link ] Upanishad Ganga episodes
  • [ link ] Kathopanishad Kathakali

brahma sūtras (yukti)
  • [ link ] brahma sūtras with the vaiyāsika nyāya māla