The Yoga Tārāvalī is a source often quoted within Aṣṭāṅga Yoga Communities because of the adoption of its opening verse (along with one of the traditional opening prayers to Patañjali) as their opening prayer dedications.
However, it is a full text in itself, has 29 verses in total and is primarily a teaching on Haṭha Yoga. It was one of the Haṭha texts taught by T Krishnamacharya to TKV Desikachar, along with the more popular medieval Haṭha Pradīpikā and other lesser known Haṭha texts such as the Yoga Yājñavalkhya.
The Yoga Tārāvalī has been attributed by some to the 8th Century Advaita Founder Śaṅkara. However it should be noted here that there is an Indian tradition of attributing texts or teachings to some ancient respected historical source as a form of humility on the part of the presenter, or perhaps to lend an immediate sense of provenance if seen to be originating from an authentic historical source.
The Yoga Tārāvalī is one such example where a thorough examination of the text in relation to a study of the comparative chronology of both the textual content and the Haṭha Yoga techniques discussed raises questions as to both the dating of the text and because of that its authorship being attributed to Śaṅkara.
For example quoting from the well respected and scholarly attested ‘Encyclopedia of Indian Philosophies’ volume X11 on ‘Yoga: India’s Philosophy of Meditation’ page 574.
“This small work in 29 verses is considered to be
an authoritative work on Rāja Yoga and Haṭha Yoga.
It is attributed to Śaṃkarācārya, but that attribution is highly unlikely.
The author and the date of the text are unknown.”
The common opinion amongst scholars of Haṭha Yoga is that it originates from the 14th century.
Along with the text as a downloadable PDF there is also a recording of TKV Desikachar chanting the text, from my personal library of recordings when studying with him.