India, Feb. 20 -- It is essentially a test meant to distinguish bots from humans, block the former and usher in the latter. That's why it's called the Completely Automated Public Turing test to tell Computers and Humans Apart. But because of its vast reach, and stellar text recognition capabilities, CAPTCHA software has been used in a range of other ways. Take a look.

HELPING RESEARCHERS READ ANCIENT TEXTS

For decades now, libraries, publishing houses and media companies attempting to digitise texts have run into a timeless problem: that of people gathering to squint at a word and go: What does that say?!

In some cases, manuscripts have frayed; in others, old newsprint has faded.

Using CAPTCHA, it turned out that scattered multitudes ...