There are many who would have you believe that the only writings that can be called scripture are those that support their own beliefs, sect or religion. Maybe none are so bad at this as the Christian religions. They quote from The New Testament and reinforce their authority to do so from the same book, yet can not see that at the time that this collection of letters and documentaries were writen, they were not classified as scripture.

The following are definitions of the word 'scripture'.

scripture - Collaborative International Dictionary of English v.0.48 :
  Scripture \Scrip"ture\ (?; 135), n. [L. scriptura, fr. scribere,
     scriptum, to write: cf. OF. escripture, escriture, F.
     ['e]criture. See Scribe.]
     1. Anything written; a writing; a document; an inscription.
        [1913 Webster]
              I have put it in scripture and in remembrance.
                                                    --Chaucer.

any book or body of writings, esp. when regarded as sacred by a particular religious group 

ENCARTA DICTIONARY:

This dictionary list amongst the meanings for the word scripture, the following:

Sacred texts: Any sacred writing or text.

Authoritive Statement: A statement regarded as authoritative

Below are I have listed some names of writings that can be classified as scripture, together with the groups that generally use them.

 

Scripture(s) Group
Old Testament (Tanakh) Judaism; Christianity (different compilations for Jews, Catholics, Orthodox, and Protestants)
Talmud Judaism
Midrash Judaism
New Testament Christianity
Qur'an Islam
Sunnah (from hadith) Islam: Sunni
Nahjul Balagha Islam: Shiite
Avesta Zoroastrianism
Vedas Hinduism
Upanishads Hinduism
Bhagavad Gita (in the Mahabharata) Hinduism
various Puranas (Vishnu Purana, Shiva Purana, Skanda Purana, Linga Purana, Garuda Purana, Matsya Purana, etc.) Hinduism: newer movements, Vaishnavite, Shaivite
Tantras (including Kularnava Tantra) Hinduism
sutras, and their commentaries Hinduism
Vachanas Lingayats (Virashaiva)
Adi Granth Sikhism
Purvas (12 angas including Acarangasutra and Sutrakritanga, 34 angabahya including Uttaradhyayana Sutra and Kalpa Sutra. Also: Upasakdasanga Sutra, Dashavaikalika Sutra, and Nandi Sutra) Jainism: Shvetambara
Purvas (small number; reject most Shvetambara Purvas) Jainism: Digambara
large number of scholastic expositions (anuyoga): Samayasara, Niyamasara, Pravacanasara, and Pancastikaya; Anupreksa; Samadhishataka of Pujyapada; Tattvarthasutra of Umasvati Jainism: Digambara
Tattvarthasutra Jainism (minor differences between Digambara and Shvetambara versions)
Other separate books of Jain Canon: Sanmatitarka, Gomattasara, Jayadhavala, Adipurana, Dvatrimshika, Aptamimamsa, Mulacara, Ratnakarandasravakacara, Sagaradharmamrita Jainism
Pali Tripitaka Buddhism
Jataka stories (semi-cannonical) Buddhism: Theravada
Visuddimagga or Path of Purification (semi-cannonical) Buddhism: Theravada
Questions of King Milinda (semi-cannonical) Buddhism: Theravada
Chinese Tripitaka Buddhism: Mahayana
Tibetan Tripitaka Buddhism: Mahayana
Lotus Sutra (Saddharma-Pundarika) Buddhism: Mahayana
Sukhavativyuha Sutras Buddhism: Mahayana: Pure Land
Meditation on Buddha Amitayus (Amitayur Dhyana Sutra) Buddhism: Mahayana: Pure Land
Garland Sutra (Avatamsaka Sutra) Buddhism: Mahayana: Kegon/Hua-yen
Perfection of Wisdom in Eight Thousand Lines (Astasahasrika Prajnaparamita Sutra) Buddhism: Mahayana
Sutra of Hui Neng (Platform Sutra) Buddhism: Mahayana: Zen
Lankavatara Sutra Buddhism: Mahayana: Zen
Mahaparinirvana Sutra; Surangama Sutra Buddha; Golden Light Sutra (Suvarnaprabhasottama) Buddhism: Mahayana
writings of Nagarjuna, Shantideva, Aryadeva, Vasubandhu, Dharmakirti, Gyalwa Longchenpa, Sakya Pandita, Milarepa, and Lama Tsongkhapa Buddhism: Tibetan
Mulamadhyamaka Karika and Precious Garland Buddhism: Tibetan
Guide to the Bodhisattva's Way of Life (Bodhisattvacharyavatara) Buddhism: Tibetan
Hevajra Tantra; Kalacakra Tantra; Guhyasamaja Tantra Buddhism: Tibetan
Tibetan Book of the Dead (Bardo Thodol) Buddhism: Tibetan
Five Classics: Book of Songs; Book of History; Spring and Autumn Annals; Book of Ritual; I Ching (Book of Changes) Confucianism (I-Ching is also cannonical for Taoism)
Four Books: Analects; the Great Learning; the Doctrine of the Mean; the Mencius Confucianism
Tao Te Ching Taoism
Chuang-tzu Taoism
Treatise on Response and Retribution (T'ai-Shang Kan-Ying P'ien) Taoism: popular religious Taoism
Tract of the Quiet Way (Yin Chih Wen) Taoism: popular religious Taoism
Kojiki Shinto
Nihon Shoki Shinto
K-oki Tenrikyo
Ofudesaki Tenrikyo
Mikagura-uta Tenrikyo
Michi-no-Shiori Omoto
Johrei Sekai Kyusei Kyo
Goseigen Mahikari
Nectarean Shower of Holy Doctrines Seicho-no-Ie
Song of the Angel Seicho-no-Ie
Holy Sutra for Spiritual Healing Seicho-no-Ie
Divine Teachings of Kyososama Shinreikyo
Chun Boo Kyung ancient Korean
Gleanings from the Writings of Baha'u'llah Bahai Faith
Book of Certitude (Kitab-i-Iqan) Bahai Faith
Hidden Words of Baha'u'llah Bahai Faith
Epistle to the Son of the Wolf Bahai Faith
Book of Mormon Christianity: Church of Jesus Christ of Latter-day Saints
Doctrine and Covenants Christianity: Church of Jesus Christ of Latter-day Saints
Pearl of Great Price Christianity: Church of Jesus Christ of Latter-day Saints
Science and Health with Key to the Scriptures Christianity: Christian Science
Dianetics Scientology

This topic is examined in more detail either from the website that I obtained this list from : http://www.adherents.com/adh_influbooks.html or from links available on that site.

Finally I have to ask myself the following. When the world seems full of these sacred writings, why is it that the individual religions want to retain their individuality and not share in the wealth of material that the Creator, the Father of all mankind, has provided for us?