A lightweight privacy focused alternative to Discus. Maker says this about upcoming captcha support:

"""
Captcha support is in the pipeline! :)
With something painless like recaptcha, you can ward off most of the spammers. It's painless for real users because you don't have to select image every time if you're logged into your Google account. For the rest, there'll be a moderation dashboard soon.
"""

I somehow don't trust the privacy marketing anymore.