Neil Harris wrote:
Indeed it would be possible: what would be needed would be a word list of about a thousand short words, for each language that needed its own captchas, since the captcha software uses these to build its challenge strings. It _might_ be possible to start with a set of common words in English, and to use Wiktionary to choose the nearest equivalents in each language.
However, I also think that it would be a good idea to have captchas in non-Latin scripts as well: presumably many Arabic or Thai readers have the same problems recognizing Latin characters that readers of Latin scripts would have with Arabic or Thai characters. We could always offer a Latin-script alternative as a fallback.
-- Neil
I've filed Bug 5309 http://bugzilla.wikimedia.org/5309 on this.