I've been in touch with TED, they're happy for an Instant Answer to be developed using their API :) see the email below. I will get to work on the Instant Answer this week.

JUN 30, 2014 | 03:14PM EDT

Hello Des,

Thanks for your interest in developing with the TED API! As long as you follow DuckDuckGo’s
requirements for use, we are happy to have you develop an Instant Answer plug in for TED queries.

If you end up hitting our rate limits for the base level API please let us know and we will review your
app for a possible API key upgrade.

Warm regards,
posted by <hidden> • 4 years and 5 months ago Link