Texts 250-55 and 257 (CBETA, T08n0250-55, 257) are seven versions of the Heart Sūtra, and four of them bear the same name. Text 250 is the earliest translation, done by Kumārajīva (鳩摩羅什, 344-413). Text 256 is a Chinese transliteration of the Sanskrit text, phonetically rendered by the Chinese master Xuanzang (玄奘, 600- or 602-664), which matches his translation in text 251. Text 257 is the latest version, translated by Dānapāla (施護, dates unknown) from Udyāna (in northern India), who went to China in 980, during the Northern Song Dynasty. These Chinese translations may be based on different Sanskrit texts, but all of them include the key message, starting with the words "form is no different from emptiness," and ending with the mantra.
Sūtra 15-17 are in one-to-one correspondence to Texts 250-52, which were translated into Chinese respectively by Kumārajīva, Xuanzang, and Dharmacandra (法月, 653-743). Text 251, translated by Xuanzang, is the popular version that Chinese Buddhists recite from memory. It is the shortest version, a virtual excerpt of Text 250, translated by Kumārajīva. Text 252, translated by Dharmacandra, is the longest of the seven versions. Like Text 251, it has also adopted many words in the Kumārajīva translation.
There are many English versions of the Heart Sūtra, variously translated from Chinese, Sanskrit, and Tibetan texts. Text 251 alone has several English translations online. Also, Buddhist groups have their own in-house translations. It seems no one is satisfied with the available translations.
Each version of the Heart Sūtra states, “Dharmas, with empty appearances, have neither birth nor death, neither impurity nor purity, neither increase nor decrease.” This is the absolute truth that dharmas are empty and have in true reality no birth or death. For example, a dharma, whether each of the five aggregates, each of the twelve fields, each of the eighteen spheres, each of the Twelve Links of Dependent Arising, or each of the Four Noble Truths, is in effect emptiness.
Furthermore, as dharmas are in effect emptiness, emptiness is in effect dharmas vivid in manifestation. This is the Middle Way. Therefore, Bodhisattvas, with the understanding that there is nothing to attain, will still attain the ultimate nirvāṇa, verifying that there is nothing to attain. Such realization is prajñā-pāramitā, the wisdom that can cross one over to the opposite shore of Buddhahood, with no fear or hindrance.