Patanjali's Yoga Sutras form a systematic treatise concerned with defining the most important elements of Yoga theory and practice. The Yoga Sutras consist of 195 aphorisms or sutras, though some variant texts have 196 also.
There are many commentaries on the Yoga Sutras of Patanjali, which occasioned further subcommenatries and glosses. There are Bhashyas (original explanatory works containing much background information), Vrittis (original commentaries offering word-by-word explanations), Tikas (glosses on commentaries), and Upatikas (subglosses on glosses). Typical example of a Tika are Vacaspati Mishra’s Tattva-Vaisharadi and Vijnana Bhikshu’s Yoga-Varttika – both of which are glosses on Vyasa’s Yoga-Bhashya, whereas the Patanajal-Rahasya by Raghavananda for instance, belongs to the category of subglosses.
The Yoga-Bhashya of Vyasa
The oldest extant commentary on the Yoga-Sutra is the Yoga-Bhashya by Vyasa
The first major commentary after the Yoga-Bhashya is Vachaspati Mishra’s Tattva-Vaisharadi (“Clarity of Truth”). Vachaspati Mishra lived in the ninth century.
From the eleventh century, there are two important works. The first is the Arabic translation of the Yoga-Sutra prepared by the renowned Persian scholar al-Biruni – a rather free rendering that may well have exercised a lasting influence on the development of Persian mysticism. The other work is the subcommentary known as Raja-Martanda (“Royal Sun”), or Bhoja-Vritti, by King Bhoja, who lived from 1019 to 1054 C.E.
The next major commentary is Shri Shankaracharya's Vivarana (Exposition) on the Yoga-Bhashya of Vyasa , although from the fourteenth century we also have a systematic account of Patanjali's Yoga in Madhava's Sarva-Darshana-Samgraha , which as the title indicates, is a compendium (samgraha) of all (sarva) major philosophical systems (darshana) of India.
Vijnana Bhikshu authored an elaborate commentary called Yoga-Varttika and the Yoga-Sara-Samgraha which is a digest of his voluminous treatise. Vijnana Bhikshu was a renowned scholar who interpreted Yoga from a Vedantic point of view.
Bhasvati commentary on the Yoga Sutras of Patanjali, was composed in the twentieth century by Swami Hariharananda (1869-1947), who was an adept in Samkhya-Yoga.