Supertitles

baltimoresun.com - Audiences hang on opera's every word

This article is wonderful in describing the issues that designers of supertitles have. (And even the technological issues). It is a good read for people who want to know how these things work, and why you shouldn't be scared of foreign language productions that have them, both as the cast and the audience. They are so much better than any headphone based systems, as they keep the cast in the center of the attention of the audience.