There are six Darshan Shastras called the six schools of philosophy. They are: (1) Poorv Mimansaby Sage Jaimini, (2) Nyay by Sage Gautam, (3) Vaisheshik by Sage Kanad, (4) Sankhya by Bhagwan Kapil, (5) Yog by Sage Patanjali, and (6) Uttar Mimansa (Brahm Sutra) by Bhagwan Ved Vyas. All the six Darshan Shastras are in sutra form.
Source: wiktionary