When its image-recognition software can't interpret a passage of aged or faded text, it further distorts the image and serves it up as a CAPTCHA. That means the project not only produces an enormous output of digitized records for preservation purposes--it also filters text to find far more difficult words for computers to recognize.

FORBES: Magazine Article

Just highlight the word or passage of text in the browser window that you are interested in and then right-click it and select the Hyperwords menu to see your options.

BBC: Movie Profiler.com website