It's called Usenet, and it still exists, though it's not as active as it used to be.
Google Groups is decent for searching old Usenet posts (though they've removed the "Advanced Search" feature), but horrible for posting. There are a number of NNTP clients (including Firefox) and free or cheap servers (I use news.eternal-september.org).
(To be clear, Google Groups includes both an interface to Usenet newsgroups and Google's own non-Usenet groups. It's probably ok for the latter, but they seriously botched the Usenet interface.)
The question was "What's the equivalent to it nowadays?"... unless there's something else that I'm missing, I think google groups is where such discussions take place and that's where I've participated in for the last decade or so.
I don't think newsgroups are only used for piracy. Most open source products have a Google Group associated with it unless they're using the discussion on Github or Stackoverflow chat / IRC.
You can find the original thread here: https://groups.google.com/forum/#!topic/comp.os.minix/wlhw16...