Old English Dictionary (Bosworth-Toller III)
The Anglo-Saxon Dictionary Project also has Bosworth and Toller's Anglo-Saxon Dictionary in electronic
form (site under construction).
Old English Dictionary (Hall)
Here you can find scans of all pages of Hall's
Concise Anglo-Saxon Dictionary
(2nd ed.). Very helpful if you do not have access to a printed copy.
Middle English Dictionary
The searchable Middle English Dictionary can be accessed through the university network.
Dictionary of the Scots Language
Incorporates electronic editions of the two major historical dictionaries of the Scots language: the Dictionary of the Older Scottish Tongue (DOST) and the Scottish National Dictionary (SND)