Chaucer's 'Troilus and Criseyde'
Detailed study guide with much useful background information.

Berkeley: Chaucer's Troilus and Criseyde
Available as complete text or each book separately.

Troilus And Criseyde
Rendered into modern English spelling; this site also includes the text of Robert Henryson's "The Testament of Cresseid" and the translator's prefatory comments. All are in Portable Document Format.

Troilus and Criseyde
A modernized version of Chaucer's Troilus and Criseyde, eliminating archaic words and phrases, but retaining Chaucer's diction and rhymes wherever possible.

Troilus and Criseyde
Plain Text in original Middle English on a single page.

Troilus and Criseyde
In plain text, or as a zip file, at Project Gutenberg.