Diachronic
Language Change Database [a fully searchable resource with 'the results of a large number of articles that document how the English language has changed in the course of its history']
BHO - British History Online ['a digital library of primary and secondary sources on medieval and modern history of Great Britain and Ireland'; subscription is required, but most content is free to access]
English Historical Documents Online [an online version of the print series; institutional subscription is required]
The Records of the Parliament of Scotland to 1707 ['a fully searchable edition of the proceedings of the Scottish parliament from 1235 to the union of 1707']
Old English
Fontes Anglo-Saxonici [identifies 'all written sources which were incorporated, quoted, translated or adapted anywhere in English or Latin texts which were written, or are likely to have been written, in Anglo-Saxon England, including those by foreign authors']
Electronic Sawyer ['presents in searchable and browsable form a revised, updated, and expanded version of Peter Sawyer's Anglo-Saxon Charters: an Annotated List and Bibliography, published by the Royal Historical Society in 1968']
The Language of Anglo-Saxon Charters (LASC) database (project homepage) ['allows users to explore the varied uses of Latin and the Anglo-Saxon vernacular, Old English, in the extraordinarily rich corpus of 1500 surviving charters from Anglo-Saxon England']
The Language of Landscape (Langscape): Reading the Anglo-Saxon Countryside ['an on-line searchable database of Anglo-Saxon estate boundaries, descriptions of the countryside made by the Anglo-Saxons themselves']
Allen J. Frantzen, Anglo-Saxon Penitentials: A Cultural Database [contains 'all the vernacular penitentials that survive from Anglo-Saxon England ... which have never before been edited and translated as a corpus']
Berwickshire Place-Name Resource ['offers early forms and analysis for all 1,224 Berwickshire place-names on the Ordnance Survey Landranger map series (1:50,000)']
Manchester Eleventh-Century Spelling Database [recovery and reconfiguration of the original data developed at Manchester]
NerthusV3 [online lexical database of OE that contains 'predicate, alternative spellings, category, translation, inflectional morphology and inflectional forms of the lexeme']
Freya ['lemma, alternative spellings, lexical category, inflectional forms, morphological analysis, meaning and references of the lexical items found in … glossaries of editions and studies in the Old English language']
CLASP - A Consolidated Library of Anglo-Saxon Poetry [a project at the University of Oxford which 'will produce for the first time a comprehensive online and interactive library, marked up through TEI P5 XML to facilitate the identification of idiosyncratic features of sound, metre, spellings, diction, syntax, formulas, themes, and genres across the corpus']
Middle English
DIMEV: Digital edition of the Index of Middle English Verse [based on the Index of Middle English Verse (1943) and its Supplement (1965)]
Gersum Project - The Scandinavian Influence on English Vocabulary ['Each entry is annotated with information about the form and meaning of the word..., its regional and historical distribution, and its etymology'.]
Database of Middle English Romance ['Key information, including (where known) date and place of composition, verse form, authorship and sources, extant manuscripts and early modern prints, is provided for each romance, as is a full list of modern editions, and a plot summary designed to allow readers to negotiate more easily the extraordinary diversity of the genre.']
Middle English Remedies Database (MER database) [created by Chelsea Rae Silva (University of California, Riverside): 'a searchable, open-access database of vernacular medical recipes, selected from manuscripts composed in England between 1300 and 1600']
Early Modern English
Linguistic DNA, Concept Modelling Interfaces ['The aim of Linguistic DNA was to understand the evolution of early modern thought by modelling the semantic and conceptual changes which occurred in English discourse (c.1500-c.1800). The project used information extraction techniques and data visualisation to identify lexical patterns in 250,000 texts.']
Shakespeare's Monologues ['A complete database of Shakespeare's Monologues. The monologues are organized by play, then categorized by comedy, history and tragedy.']
Dramatic Extracts (DEx) ['an online, searchable database of dramatic extracts found in seventeenth-century manuscripts']
Early Modern Recipes Online Collective (project description) ['an international group of interdisciplinary scholars working to crowd-source, transcribe, and tag English language recipe texts dating from c. 1550–1700']
Early Modern Maritime Recipes ['compiles a record of extant recipes by digitizing and transcribing recipes from archival collections throughout the Maritime provinces']
Marie-Louise Coolahan et al., RECIRC (The Reception and Circulation of Early Modern Women's Writing, 1550-1700) ['a database about which female authors were read, by whom, and how texts by women circulated in the 16th and 17th centuries']
DREaM (Distant Reading Early Modernity) database [planning to 'make a massive corpus of some 44,000+ early modern English texts readily available for macro-scale textual analysis and visualization']
Database of Early English Playbooks (DEEP) ['an easy-to-use and highly customizable search engine of every playbook produced in England, Scotland, and Ireland from the beginning of printing through 1660']
Early Modern Women's Complaint Poetry Index ['a first and last line index of female-authored complaint poetry in English and Scots from the period 1530 to 1680']
Late Modern English
Eighteenth-Century English Grammars (ECEG) (web interface) ['a database which primarily compiles information about eighteenth-century English grammars as gathered from earlier bibliographies, collections and scholarly studies published over the last hundred years (1903-2011)']
ECEP (Eighteenth-Century English Phonology) Database ['designed for the study of eighteenth-century English phonology, allowing users to investigate the social, regional and lexical distribution of phonological variants in eighteenth-century English']
Thomas Gray Archive ['a fully browsable, searchable and annotated digital archive of the life and works of Thomas Gray (1716-1771)']
The British Newspaper Archive [planning to 'digitise up to 40 million newspaper pages from the British Library's vast collection over the next 10 years']
HUGE (Hyper Usage Guide of English) database ['Users can expect to find detailed advice on many usage problems in the English language, and will be able to compare usage advice across guides, acrosse [sic] time, and across different varieties of English']
World Englishes
eWAVE - the Electronic World Atlas of Varieties of English ['an interactive database on morphosyntactic variation in spontaneous spoken English mapping 235 features from a dozen domains of grammar in now 51 varieties of English and 26 English-based Pidgins and Creoles in eight Anglophone world regions']
Yale Grammatical Diversity Project - English in North America [formerly 'Morpho-Syntactic Atlas of Varieties of English (MSAVE)', 'we have been gathering information about syntactic variation in North American English from a number of different sources']
British Library, Accents and Dialects ['The selection available here comes from the 3.5 million sounds held in the British Library.']
Steven H. Weinberger (George Mason University), Speech Accent Archive ['The speech accent archive uniformly presents a large set of speech samples from a variety of language backgrounds.']