More and more tablature is available for free viewing and download via national and international book digitisation projects, as well as music-specific websites.
The Lute Library has links to downloadable tablatures, listed by historical printed and manuscript sources, by date, composer, country and repertoire, etc: web.archive.org/web/20160125185028/www.lutelibrary.com/home
The Choral Public Domain Library, www1.cpdl.org/wiki/index.php/Main_Page
IMSLP, Petrucci Music Library (incorporating the Werner Icking archive) imslp.org/wiki/Main_Page
Early Music Online, Royal Holloway College, 34 lute sources from the British Library, repository.royalholloway.ac.uk/access/hierarchy.do?topic=52facdbd-19ce-2b92-dbd5-434289d29e8b&sort=rank&page=1
Note: IMSLP can be searched by instrument, eg lute, For 2 Lutes, For 3 Lutes. Here is the link for lute duets:
imslp.org/index.php?title=Category:For_2_lutes&transclude=Template:Catintro
Score Exchange, searchable for 'lute': www.scoreexchange.com/search?q=lute
The Tufvesson site www.lysator.liu.se/~tuben/scores/.
Baroque opera scores, Lully Collection at University of North Texas Libraries: digital.library.unt.edu/explore/collections/jblc/browse/
Important sites for ballads and early song are Lindahl’s Sixteenth century ballads project, www.pbm.com/~lindahl/ballads/
and the Dutch Liederenbank: www.liederenbank.nl/
www.archive.org,
Project Gutenburg www.gutenberg.org/,
The online Books page: onlinebooks.library.upenn.edu/
EEBO, Early English Books Online: eebo.chadwyck.com/home
Bibliotheque Nationale de France site www.bnf.fr/fr/acc/x.accueil.html
Gallica gallica.bnf.fr/?lang=en
Hispanic sources at Biblioteca Digital Hispanica www.bne.es/en/Catalogos/BibliotecaDigitalHispanica/Inicio/
Bayerische Staatsbibliothek Digitale Sammlung: daten.digitale-sammlungen.de/~db/ausgaben/uni_ausgabe.html?projekt=1328176523&ordnung=sig&recherche=ja&l=de
Cambridge Digital Library Music Collection: cudl.lib.cam.ac.uk/collections/music
Danish National Library music collection www.kb.dk/da/nb/samling/ma
Danish Royal Collection can be searched at the REX website: rex.kb.dk/
The Danish Centre for Music Publication www.kb.dk/en/nb/dcm/index.html
Medieval and Early Modern Manuscripts Online: scriptorium.english.cam.ac.uk/manuscripts/
Polona Polish digital library: polona.pl/
UR Research at the University of Rochester: urresearch.rochester.edu/viewInstitutionalCollection.action;jsessionid=1D40F3D2FC3533A761BA61AF4BAE59DE?collectionId=63
National Library of Scotland (includes special music collections) digital.nls.uk/special-collections-of-printed-music/pageturner.cfm?id=97135480
Neomusic (some free content, some for sale) www.musicaneo.com
www.epubli.de an online German-based publisher.
Various tablature software packages websites have large amounts of downloadable tablature, typeset in their respective packages, on the site or via links to enthusiasts' websites.
See also:
Allan Alexander’s site www.guitarandlute.com/lutetab.html
Asteria, medieval music for lute and voice: www.asteriamusica.org/medievallute.info/
Jo Bringman's facsimile links: www.jobringmann.de/
Nancy Carlin Grounds and Divisions: www.groundsanddivisions.info/
Richard Civiol’s Luth-Lirbrairie: luthlibrairie.free.fr/
Wayne Cripps's Tablature in PDF and postscript format:www.cs.dartmouth.edu/~wbc/tab-serv/tab-serv.cgi
Jean Daniel Forget, Baroque lute scores (listed by manuscript and by composer):luthbaroque.fr/majeur.htm#
Christoph Dalitz's site: music.dalitio.de/instr/parts.html#lute
Gavin Emery's Baroque Guitar site, now archived to: web.archive.org/web/20070816170352/www.baroqueguitar.net/
Donatella Galletti’s page web.tiscalinet.it/awebd/music.htm
Sarge Gerbode, large library of modern scores in Fronimo, midi and PDF and cleaned-up facsimiles: www.gerbode.net/; alphabetical by composer: www.lute.ru/gerbode/ft2/composers/ Alexander Keliris has created a search engine for this very large collection: keliris.dev/lute-search/
Anton Hoger’s page of lute duos, trios, quartets antonslutepage.webnode.com/
Luth-librairie paulduif.home.xs4all.nl/luth-librairie/
Ceza Mateus, luthier, music from Barbe Manuscript: www.mateus-lutes.com/misc.html
Thomas Schall: www.lautenist.de/Renaissance.htm www.lautenist.de/Barock.htm and www.lautenist.de/Ensemble.htm
Andi Schlegel and F P Goy's accords nouveaux site: accordsnouveaux.ch
Peter Steur’s database of music for the baroque lute: with links to numerous downloadable sources: mss.slweiss.de/index.php?id=0&type=index&lang=eng
Roman Turovsky, Polyhymnion site polyhymnion.org/swv, including Karl Ernst Schroeder (reconstructed Weiss duets) under Robert Barto’s pages polyhymnion.org/barto/charlie1.pdf
Clive Titmuss, Early Music Studio, under Tablatures: earlymusicstudio.com/tablatures/tablatures-for-lute-and-guitar/
Alain Veylit: django.musickshandmade.com/pages/old-site
Igor Varfolomeev’s lute and guitar site; many of these also have soundfiles www.lute.ru/home_eng.htm
Arto Wikla, music by Robert de Visee www.cs.helsinki.fi/u/wikla/mus/visee.html
Richard Yates, music by Vincenzo Galilei and a few others in tab, and guitar transcriptions yatesguitar.com/scores.php
The Delcamp French language guitar discussion page has a list of all printed 16th century sources and numerous classical guitar transcriptions: www.guitareclassiquedelcamp.com/partitions/luth.html
Xavier Diaz Latorre, links to downloadable tablature and books:
Ed Durbrow's list of sites with downloadable tab: www9.plala.or.jp/edurbrow/webtab.html
On Thomas Schall’s site: www.lautenist.de/TablaturesOnline.htm
On Arto Wikla's site: www.cs.helsinki.fi/u/wikla/mus/MusExamp.html
Peter Martin's database of downloadable facsimiles:www.silvius.co.uk/
Ning website (mostly guitar) earlyguitar.ning.com/page/scores-1
Lute Society of America links to downloadable facsimiles: lutesocietyofamerica.org/resources/external-resources/lute-tablature-sites/