The complete Middle English Dictionary from the University of Michigan is now free online.
“The print MED, completed in 2001, has been described as “the greatest achievement in medieval scholarship in America.” Its 15,000 pages offer a comprehensive analysis of lexicon and usage for the period 1100-1500, based on the analysis of a collection of over three million citation slips, the largest collection of this kind available. This electronic version of the MED preserves all the details of the print MED, but goes far beyond this, by converting its contents into an enormous database, searchable in ways impossible within any print dictionary.”
Here’s the University of Michigan press release which gives all the background.
Edited to add press release.