Sources of Tabulatures online
The LSA offers a great collection of digital facsimiles.
a great source for online lute tabs is Sarge Gerbode's page
on the site of Alain Veylit (developer of Django) you'll find many pieces, too.
There is also a "Faksimile Section"
Wayne Cripps Tab-Files offer many Tablatures produced with the pioneering tablature setting program.
abc Tab Files produced in the platform independend abc tab format.
The Fronimo User Group on Yahoo requires registration but offers many tablature set in Fronimo
Allan Alexander offers a mixtiure of commercial and free tablatures for download
Michael Treder (generally an interesting site, mainly in german)
The reconstructed Weiss duets (by Charly Schröder)
Arthur Ness edition of the works by Marco d'Aquila
Clive Titmuss offers a lot of music - mainly for the baroque lute
Rob MacKillop - music for several different instruments, among them baroque lute, vihuela and baroque guitar
Arto Wikla's links to endless further lute resources (he himself offers a lot of interesting music, too)
Peter Martin's lute and early music database
Wroclaw 2002 - a lute manuscript online
The Vaudry de Saizenay manuscript now available in colour on the Besancon library site