Kashyapa is a common ancient name, referring to many different personalities in the ancient Hindu and Buddhist texts.
Ka?yapa, alternatively kacchapa, means "turtle" in Sanskrit. According to Michael Witzel, it is related to Avestankasiiapa, Sogdianky?ph, New Persian ka?af, ka?(a)p which mean "tortoise", after which Kashaf R?d or a river in Turkmenistan and Khorasan is named. Other relations include to Tokarian Bkacc?p ("brainpan"), Polishkacap (czerep, "brainpan", "hardliner"),Tokarian Ak?ccap ("turtle", "tortoise").Frits Staal agrees that Ka?yapa means tortoise but believes that it is a non-Indo-European word.
Kashyapa is mentioned in other Vedas and numerous other Vedic texts. For example, in one of several cosmology-related hymns of Atharvaveda (~1000 BCE), Kashyapa is mentioned in the allegory-filled Book XIX:
Undisturbed am I, undisturbed is my soul,
undisturbed mine eye, undisturbed mine ear,
undisturbed is mine in-breathing, undisturbed mine out-breathing,
undisturbed my diffusive breath, undisturbed the whole of me.
Thereafter rose Desire in the beginning, Desire the primal seed and germ of Spirit,
O Kama dwelling with the lofty Kama, give growth of riches to the sacrificer, (...)
Prolific, thousand eyed, and undecaying, a horse with seven reins Time bears us onward,
Sages inspired with holy knowledge mount him, his chariot wheels are all the worlds of creatures.
Kala [Time] created yonder heaven, and Kala made these realms of earth,
By Kala, stirred to motion, both what is and what shall be, expand, (...)
Kala created living things and first of all Prajapati,
From Kala self-made Kasyapa, from Kala Holy Fire was born.
His name appears in Patanjali's ancient bhasya on verse 1.2.64 of Pini. His name is very common in the Epic and Purana literature.
In Buddhist Pali canonical texts such as Digha Nikaya, Tevijja Sutta describes a discussion between the Buddha and Vedic scholars of his time. The Buddha names ten rishis, calls them "early sages" and makers of ancient verses that have been collected and chanted in his era, and among those ten rishi is Kassapa (the Pali spelling of Kashyapa in Sanskrit).[note 2]
Kashmir, the northern Himalayan region of the Indian subcontinent got its name from Kashyapa Rishi. The name Kashmir, states Christopher Snedden, is a shortened form of "Kashyapa Mir" or the "lake of the sage Kashyapa", or alternatively derived from "Kashyapa Meru" or the sacred mountains of Kashyapa.
In ancient texts of Greece, linked to the expedition of Alexander the Great, this land has been called "Kasperia", possibly a contraction of "Kasyapamira". The word "Kaspapyros" appears in Greek geographer Hekataois text, and as "Kaspatyros" in Herodotus who states that Skylax the Karyandian began in Kaspatyros to trace the path of Indus river from the mountains to where it drained in the sea. Kaspatyros may be same as Kaspa-pyrus or Kasyapa-pur (city of Kashyapa) in other texts.
Kashyapa is revered in the Hindu tradition, and numerous legends and texts composed in the medieval era are reverentially attributed to him in various Hindu traditions. Some treatises named after him or attributed to him include:
Kashyapa Samhita, also called Vriddajivakiya Tantra or Jivakiya Tantra, is a classical reference book on Ayurvedic pediatrics, gynecology and obstetrics. It was revised by Vatsya. The treatise is written as a tutorial between the medical sage Kashyapa and his student named Vriddhajivaka, and mostly related to caring for babies and diseases of children.
Kashyapa Jnanakandah, or Kashyapa's book of wisdom, is a 9th-century text of the Vaishnavism tradition.
Ka?yapa dharmasutra, likely an ancient text, but now believed to be lost. The text's existence is inferred from quotes and citations by medieval Indian scholars.
Ka?yapa sangita, likely another ancient text, but now believed to be lost. A treatise on music, it is quoted by Shaivism and Advaita scholar Abhinavagupta, wherein he cites sage Kasyapa explanation on viniyoga of each rasa and bhava. Another Hindu music scholar named Hrdanyangama mentions Kashyapa's contributions to the theory of alankara (musical note decorations).
Kasyapasilpa, also called Amsumad agama, Kasypiya or Silpasastra of Ka?yapa, is a Sanskrit treatise on architecture, iconography and the decorative arts, probably completed in the 11th century.
Kashyapa is mentioned in numerous Hindu texts such as the Puranas and the Hindu Epics. These stories are widely inconsistent, and many are considered allegorical. For example, in the Ramayana, he is married to the eight daughters of Daksha, while in the Mahabharata and Vishnu Purana he is described as married to thirteen daughters. Some of the names of the thirteen daughters Kashyapa married in the Hindu text Vishnu Purana are different than the list found in Mahabharata. Some texts describe him as son of Marichi and a descendant of the solar dynasty, others as a descendant of Uttamapada who married Daksha's daughters, and yet others relate Kashyapa as a descendant of Hiranya Kashyapa. These texts may correspond to different characters, all named Kashyapa.
In some Puranas, Kashyapa is said to have drained the Kashmir valley to make it inhabitable. Some interpret this legend to parallel the legend of Buddhist Manjushri draining Nepal and Tibet, wherein the "draining" is an allegory for teaching ideas and doctrines, removing stagnant waters of ignorance and extending learning and civilization into the valley. The Sindh city Multan (now in Pakistan), also called Mulasthana, has been interpreted alternatively as Kashyapapura in some stories after Kashyapa. Yet another interpretation has been to associate Kashyapa as River Indus in the Sindh region. However, these interpretations and the links of Multan as Kashyapapura to Kashmir have been questioned.
According to the ancient legends, Kashyapa reclaimed that land from a vast lake, his school was based there, and the land was named after him.
Kashyapa, in the Vishnu Purana and Vayu Purana, is attributed to be the father of the Devas, AsurasYakhsas dravidas and all living creatures with various daughters of Daksha. He married Aditi, with whom he fathered Surya or alternatively Agni, the Adityas, and in two inconsistent versions Vamana, an avatar of Vishnu, is the child of Aditi and Kashyapa. In these fables, Kashyapa is the brother-in-law of Dharma and Adharma, both of whom are also described as married to other daughters of Daksha.
^Kasyapa is mentioned in RV 9.114.2, Atri in RV 5.78.4, Bharadvaja in RV 6.25.9, Visvamitra in RV 10.167.4, Gautama in RV 1.78.1, Jamadagni in RV 3.62.18, etc.; Original Sanskrit text: ? ? ? ? ? ? 
^The Buddha names the following as "early sages" of Vedic verses, "Atthaka (either Astaka or Atri), Vamaka, Vamadeva, Vessamitta (Visvamitra), Yamataggi, Angirasa, Bharadvaja, Vasettha (Vashistha), Kassapa (Kashyapa) and Bhagu (Bhrigu)".
^Vishnu Purana: Book I, Chapter XVThe Vishnu Purana, translated by Horace Hayman Wilson, 1840. p. 112. The daughters of Daksha who were married to Ka?yapa were Aditi, Diti, Danu, Arisjht?á, Surasá, Surabhi, Vinatá, Támrá, Krodhava?á, Id?á, Khasá, Kadru, and Muni 19; whose progeny I will describe to you...Vish?u, ?akra, Áryaman, Dhútí, Twáshtri, Púshan, Vivaswat, Savitri, Mitra, Varu?a, An?a, and Bhaga
^Account of the several Manus and ManwantarasVishnu Purana, translated by Horace Hayman Wilson, 1840, Quote:"Vish?u was born of Vikunthi, as Vaikuntha, along with the deities called Vaikunthas. In the present Manwantara, Vish?u was again born as Vámana, the son of Ka?yapa by Adití. With three paces he subdued the worlds, and gave them, freed from all embarrassment, to Purandara.", Footnote 4: "The Váyu describes the Rishis (...) with some inconsistency, for Ka?yapa, at least, did not appear himself until the seventh, Manwantara. (...) The Bráhma P. and Hari Van?a have a rather different list (...)"