Rabbinic Literature freely accessible on the web (updated on Dec 8 2014)

Below are links to online whole text or nearly whole text of some rabbinic literature. I list only webpages or Google Books which number the sections and thus are easy to use. This collection of links is updated from time to time.
Such primary sources are useful when one reads articles about the Bible which quotes rabbinic materials to prove a point about social customs or Jewish methods of interpretation etc. Sometimes we wish to look up the context of the quoted rabbinic passage to ascertain what was really said.

Avot de Rabbi Nathan, Versions A&B (Hebrew)

Avot de Rabbi Nathan, Version A (Hebrew)

Avot de Rabbi Nathan, Version A (English, trans. Goldin, pdf)

Avot de Rabbi Nathan, Version A (English, trans. Goldin, Google Books)

Avot de Rabbi Nathan, Version B (English, trans. Saldarini)

Babylonian Talmud (Hebrew, English)

Deuteronomy Rabbah (Hebrew)

Ecclesiastes Rabbah (Hebrew)

Esther Rabbah (Hebrew)

Exodus Rabbah (Hebrew)

Fathers According to Rabbi Nathan---See Avot de Rabbi Nathan

Genesis Rabbah (Hebrew)

Genesis Rabbah (the first half, English)

Jerusalem Talmud (Hebrew, English)

Jerusalem Talmud: Berakhot (Hebrew, English, notes)

Jerusalem Talmud: Gittin, Nazir (Hebrew, English, notes)

Jerusalem Talmud: Maaser Seni, Challah, Orlah, Bikkurim (Hebrew, English, notes)

Jerusalem Talmud: Peah, Demay/Demai (Hebrew, English, notes)

Jerusalem Talmud: Shavuot, Avodah Zarah (Hebrew, English, notes)

Jerusalem Talmud: Terumot, Maserot (Hebrew, English, notes)

Jerusalem Talmud: Yebamot (Hebrew, English, notes)

Lamentations Rabbah (Hebrew)

Lekah Tov--See Pesikta Zutra

Leviticus Rabbah (Hebrew)

Leviticus Rabbah (English, commentary) - A Theological Commentary to the Midrash: Leviticus Rabbah - Jacob Neusner

Maimonides / Ramban's Mishneh Torah (Hebrew)

Maimonides / Ramban's Mishneh Torah (English)

Mekhilta de-Rabbi Ishmael (Hebrew, English, in eBrary, fully accessible with HK public library card password)

Midrash Rabbah (Hebrew)

Midrash Rabbah: Genesis---see Genesis Rabbah

Midrash Rabbah: Leviticus---see Leviticus Rabbah

Midrash Tanḥuma / Midrash Tanhuma (English)

Mishnah (Hebrew, English)

Mishnah (English, notes, Danby trans, 1993/2011)

Mishnah (mostly English, some Hebrew)

Mishnah--Shabbat, Erubin, Pesah, Sheqalim, Yoma (Hebrew, English, notes)

Multiple texts, search Hebrew: Sefaria.org

Numbers Rabbah (Hebrew)

Pesikta de Rab Kahana / Pesiqta de Rab Kahana / Pesiqta de-Rav Kahana (English)

Pesikta Zutra / Lekah Tov (Hebrew)

Rabbinics Resources Online

Ruth Rabbah (Hebrew)

Scripture Index of Rab. Lit--Sepher Torah HaKetuvah vehaMesorah

Sifra (English)

Sifra (Hebrew)

Sifré to Numbers / Sifre to Numbers / Sifré Numbers / Sifre Numbers (English)

Sifré to Deuteronomy (English)

Song of Songs Rabbah (Hebrew)

Song of Songs Rabbah (Hebrew)

Targum of Isaiah (Jonathan) / Targum Jonathan--Isaiah (English)

Targum of Judges (Jonathan) / Targum Jonathan--Judges (Aramaic, English, commentary; start at p.329)

Targum of Ketuvim (Aramaic) (Click "Search the CAL lexical...→Text Browse→Late Jewish Literary Aramaic" [The Comprehensive Aramaic Lexicon]

Targum of Lamentations (English)

Targum of Numbers (Neofiti) / Targum Neofiti--Numbers (English)

Targum of Psalms (English)

Targum of Ruth (English trans. by Brady)

Targum of Ruth (English trans. by Levey))

Targum of Songs (English)

Targum of the Prophets (Jonathan) / Targum Jonathan of the Prophets (Aramaic) (Click "Search the CAL lexical...→Text Browse→Palestinian Aramaic, scroll down to "Canonical Jewish Literary Aramaic" [The Comprehensive Aramaic Lexicon]

Targum of Torah (Onkelos) / Targum Onkelos (Aramaic) (Click "Search the CAL lexical...→Text Browse→Palestinian Aramaic, scroll down to "Canonical Jewish Literary Aramaic" [The Comprehensive Aramaic Lexicon]

Targum of Torah (Pseudo-Jonathan) / Targum Pseudo-Jonathan of the Torah (Aramaic) (Click "Search the CAL lexical...→Text Browse→Late Jewish Literary Aramaic" [The Comprehensive Aramaic Lexicon]

Targum of Zephaniah / Targum Jonathan--Zephaniah (Jonathan; English; commentary)

Tosefta / Tosephta (Hebrew, English)

Torah Sheleimah-A 44 vols. scripture index to the Pentateuch in rab. lit.