In case you haven't heard already, Michael Halliday has died. There's a brief obituary on the Linguist List at https://linguistlist.org/issues/29/29-1633.html.

He had a major impact on UK linguistics during his time here (the 60s and early 70s), and still dominates thinking about language in our Education departments. I worked with him for six years and was deeply impressed and influenced. We should be proud of him as a great British linguist.