Anatolian

• Hethitologie Portal Mainz (HPM): https://www.hethport.uni-wuerzburg.de/HPM/index.php
  • Catalogue der Texte der Hethiter (CTH): https://www.hethport.uni-wuerzburg.de/CTH/
  • Konkordanz der hethitischen Keilschrifttafeln: https://www.hethport.uni-wuerzburg.de/hetkonk/hetkonk_abfrageF.php
• Ilya Yakubovich's Annotated Corpus of Luwian Texts (ACLT1): http://web-corpora.net/LuwianCorpus/search/
  • ACLT2: http://luwian.web-corpora.net/luwian_corpus/search
• Digital Philological-Etymological Dictionary of the Minor Ancient Anatolian Corpus Languages (eDiAna): https://www.ediana.gwi.uni-muenchen.de/​
• Hittite Monuments: http://www.hittitemonuments.com/
• Treated Passages from Hittite Texts: http://www.hittitepassages.com 
• Hittite Toponymns (HiTop): https://www.hethport.uni-wuerzburg.de/HiTop/hetgeointro.php
• Chicago Hittite Dictionary: https://oi.uchicago.edu/research/projects/chicago-hittite-dictionary-project (PDFs/eCHD)
• Zsolt Simon's List of Hieroglyphic Luwian inscriptions published since CHLI: http://agyagpap.blogspot.com/2010/10/list-of-iron-age-luwian-inscriptions.html
• HittiteTexts (web corpus; in development): https://hittitetexts.com/en 
• Craig Melchert's homepage: https://linguistics.ucla.edu/people/Melchert/Index.htm
  • Addenda & corrigenda to Hoffner & Melchert (2008), A Grammar of the Hittite Language: https://linguistics.ucla.edu/people/Melchert/Addenda&CorrigendaGrHL2.pdf

Indic

• ​Cologne Digital Sanskrit Dictionaries: https://www.sanskrit-lexicon.uni-koeln.de/
  • Grassmann, Wörterbuch zum Rig Veda: https://www.sanskrit-lexicon.uni-koeln.de/scans/GRAScan/2020/web/index.php
  • Monier Williams, A Sanskrit-English Dictionary: https://www.sanskrit-lexicon.uni-koeln.de/scans/MWScan/2020/web/webtc/indexcaller.php
  • Böhtlingk & Roth, Grosses Petersburger Wörterbuch: https://www.sanskrit-lexicon.uni-koeln.de/scans/PWGScan/2013/web/index.php
• Kevin Ryan's Rig Veda Search Tool: http://meluhha.com/rv/
• VedaWeb — Rigveda Online: https://vedaweb.uni-koeln.de/rigveda/view/index/0
• Stephanie Jamison's Rigveda Translation — Commentary: http://rigvedacommentary.alc.ucla.edu/
• Paippalāda Recension of the Atharvaveda Online (in development): http://www.atharvaveda-online.uzh.ch/home/introduction

Greek

• Thesaurus Linguae Graecae (TLG): http://stephanus.tlg.uci.edu/​
• Logeion: https://logeion.uchicago.edu/
• The Chicago Homer: https://homer.library.northwestern.edu/
• PHI Greek Inscriptions: https://epigraphy.packhum.org/
• Perseus Project: http://www.perseus.tufts.edu/hopper/collection?collection=Perseus:collection:Greco-Roman
  • Scaife Viewer: https://scaife.perseus.org/
• Database of Mycenaean at Oslo (DĀMOS): https://damos.hf.uio.no/
• Dizionario Etimologico della Mitologia Greca multilingue On Line (DEMGOL): https://demgol.units.it/index.do 
• Linear B Electronic Resources (LiBER) Project: https://liber.cnr.it/
• Mycenae Archive: https://cudl.lib.cam.ac.uk/collections/mycenae
• Attic Inscriptions Online: https://www.atticinscriptions.com/
• Aristarchus. Scholia Minora in Homerum: http://www.aristarchus.unige.net/Scholia/it-IT/Home
• Homerica. Das Fortleben Homers in den Papyri: https://papyri.uni-koeln.de/homerica/
• Telamon: Greek Inscriptions from Bulgaria: https://telamon.epistone.net/en/

Latin

• PHI Classical Latin Texts: https://latin.packhum.org/
• Whitaker's Words: http://archives.nd.edu/words.html
• Lewis & Short, A Latin Dictionary: http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.04.0059
• Thesaurus Linguae Latinae (TLL), open access: http://publikationen.badw.de/de/thesaurus/lemmata​
• Perseus Project: http://www.perseus.tufts.edu/hopper/collection?collection=Perseus:collection:Greco-Roman
  • Scaife Viewer: https://scaife.perseus.org/
• Ancient Graffiti Project (AGP): http://agp.wlu.edu/Graffiti/​
• Dictionnaire Historique et Encyclopédie Linguistique du Latin (DHELL): http://www.dhell.paris-sorbonne.fr/accueil
• Corpus Grammaticorum Latinorum: https://htldb.huma-num.fr/exist/apps/cgl/index.html

Iranian 

• Corpus Avesticum Berlinense: https://cab.geschkult.fu-berlin.de/
  • Bartholomae, Altiranisches Wörterbuch​: https://cab.geschkult.fu-berlin.de/exist/apps/cab/pages/tools/bartholomae.html

Germanic

• Wulfila Project — Gothic Bible: http://www.wulfila.be/gothic/browse/
• Referenzkorpus Altdeutsch: https://www.deutschdiachrondigital.de/zugang/
• Referenzkorpus Mittelhochdeutsch: https://www.linguistics.ruhr-uni-bochum.de/rem/
• Corpus of Historical Low German (CHLG): http://www.chlg.ac.uk/helipad/
• Deutsches Textarchiv: http://deutschestextarchiv.de/
• The York-Toronto-Helsinki Parsed Corpus of Old English Prose (YCOE): https://www-users.york.ac.uk/~lang22/YcoeHome1.htm​
• Wörterbuchnetz: https://woerterbuchnetz.de/
• Icelandic Parsed Historical Corpus (IcePaHC): https://linguist.is/icelandic_treebank/Icelandic_Parsed_Historical_Corpus_(IcePaHC)
• Altsächsisches Wörterbuch (5 ed.): http://www.koeblergerhard.de/aswbhinw.html
• Old Norse e-texts: https://etext.old.no/

Tocharian

• A Comprehensive Edition of Tocharian Manuscripts (CEToM): https://www.univie.ac.at/tocharian/

Celtic

• Electronic Dictionary of the Irish Language (eDIL): http://www.dil.ie/
• Le dictionnaire diachronique du breton (Devri): http://devri.bzh/
• Geiriadur Prifysgol Cymru (A Dictionary of the Welsh Language): http://geiriadur.ac.uk/gpc/gpc.html

Albanian

• Digitales Philologisch-Etymologisches Wörterbuch des Altalbanischen (DPEWA): https://www.dpwa.gwi.uni-muenchen.de/dictionary/
  

Armenian

• Enriched Dictionaries of Classical and Modern Armenian (CALFA): https://calfa.fr/

Baltic

• Akademinis Lietuvių kalbos žodynas (Academic Dictionary of Lithuanian): http://www.lkz.lt/ 
• Altlitavisches etymologisches Wörterbuch (ALEW 2.0): https://alew.hu-berlin.de/

Slavic

• GORAZD: The Old Church Slavonic Digital Hub: http://www.gorazd.org/?q=en 
• Tromsø Old Russian and OCS Treebank (TOROT): https://torottreebank.github.io/​

General Indo-European

• UT Austin Linguistic Research Center: https://liberalarts.utexas.edu/lrc/index.php
• Addenda und Corrigenda zu LIV2: http://www.martinkuemmel.de/liv2add.pdf
• American Heritage Dictionary — Appendix of Indo-European Roots: https://www.ahdictionary.com/word/indoeurop.html
• Glottothèque: Ancient Indo-European Grammars Online: https://spw.uni-goettingen.de/projects/aig/index.html
• Matthew Scarborough's "Guides to Indo-European Etymological Dictionaries for the Perplexed": 
  • Proto-Indo-European
  • Indic
  • Anatolian
  • Greek
  • Italic
  • Tocharian
  • Armenian
• Thesaurus Indogermanischer Text- und Sprachmaterialien (TITUS): http://titus.uni-frankfurt.de/indexe.htm
• Syntacticus — a treebank of early Indo-European languages: http://syntacticus.org/
• Digital Vatican Library: https://digi.vatlib.it/mss/
• Digital Classicist List of Current Projects Wiki: https://wiki.digitalclassicist.org/Category:Projects​
• Corpus Nummorum Online: https://www.corpus-nummorum.eu/​
• Homepage of the Indogermanische Gesellschaft: https://www.indogermanistik.org/
• UCLA Program in Indo-European Studies: http://www.pies.ucla.edu

 Ancient Near East/Mediterranean (non-IE specific)

• Chicago Assyrian Dictionary: https://oi.uchicago.edu/research/projects/chicago-assyrian-dictionary-project (​PDFs)
• Akkadian Dictionary Online: http://www.assyrianlanguages.org/akkadian/index_en.php
• Digital Corpus of Cuneiform Lexical Texts: http://oracc.museum.upenn.edu/dcclt/index.html
• Mnāmōn (Ancient Writing Systems in the Mediterranean): http://mnamon.sns.it/index.php?page=Home&lang=en
• Electronic Tools and Ancient Near East Archives (ETANA): http://etana.org/home
• Reallexikon der Assyriologie und Vorderasiatischen Archäologie (RlA) Online: https://rla.badw.de/digitaler-zugriff.html
• Etruscan Texts Project: http://etp.classics.umass.edu/
• Corpus Inscriptionum Phoenicarum: http://cip.cchs.csic.es/
• Electronic Babylonian Literature (eBL) Project: https://www.ebl.lmu.de/
• Cuneiform Inscriptions Geographical Site Index (CIGS): https://zenodo.org/record/5217600#.YV9hJBBBzKJ
• Writing Sumerian Corpus: https://corpus.writing-sumerian.assyriologie.uni-muenchen.de/
• Ebla Digital Archives (EbDA): http://ebda.cnr.it/
• Gilgamesh (Sumerian/Babylonian word study tools): http://www.gilgamesh.ch/
• The Royal Inscriptions of Babylonia online (RIBo) Project: http://oracc.museum.upenn.edu/ribo/
• Tiresias (Ancient Mediterranean Religions Source Database): http://tiresias.haifa.ac.il/
• Google Ancient Places: https://googleancientplaces.wordpress.com/project-data/
• Ancient Near East Online Event Calendar: https://anzu.digital/​

Phonology

• Phonological Software Repository: https://github.com/connormayer/phonological_software
• Kevin Ryan's Dynamic OT Tableaux Generator: http://meluhha.com/tableau/
• PhonoApps: http://www.phonology.us/
• OT-Help: https://people.umass.edu/othelp/
• Pheatures: https://linguistics.ucla.edu/people/hayes/120a/Pheatures/
• OTSoft: https://linguistics.ucla.edu/people/hayes/otsoft/
• Maxent Grammar Tool: https://linguistics.ucla.edu/people/hayes/MaxentGrammarTool/
• UCLA Phonetics Lab Archive: http://archive.phonetics.ucla.edu/
• Kwaras (Language Documentation Corpus Tool): https://sites.google.com/view/gcaballero/kwaras?authuser=0
• Sound Comparisons: https://soundcomparisons.com/#home​

General Languages & Linguistics

• Glottolog: https://glottolog.org/
• World Atlas of Language Structures (WALS): https://wals.info/
• Ethnologue: https://www.ethnologue.com/
• World Loanword Database (WOLD): https://wold.clld.org/
• Database of Cross-Linguistic Colexifications: https://clics.clld.org/
• Concepticon: concepticon.clld.org/
• Omniglot: https://www.omniglot.com/
• Polyglot (Spoken Language Construction Kit): http://draquet.github.io/PolyGlot/index.html
• Etymological Dictionary Editor (EDICTOR): https://digling.org/edictor/