Those are still out there because the licence for those specific files remains legitimate, though a 21 year old typeface is not necessarily a useful thing anymore.
That package was used as the basis of "nonfree" packages in various distributions, that would download the MS archive file and unpack/install it.
I also wonder about how much Monotype charges Microsoft.
Ubuntu of course paid for their own system faces to be designed (which I like but not enough to use on my desktop). And Firefox has its own core font family (Fira), for example, that it can use in its own products as an alternate (I think it was designed for the late not-much-lamented Firefox OS)
For a time, Microsoft had a package of "core fonts for the web" that they made some deal with Monotype for:
https://en.wikipedia.org/wiki/Core_fonts_for_the_Web
Those are still out there because the licence for those specific files remains legitimate, though a 21 year old typeface is not necessarily a useful thing anymore.
That package was used as the basis of "nonfree" packages in various distributions, that would download the MS archive file and unpack/install it.
I also wonder about how much Monotype charges Microsoft.
Ubuntu of course paid for their own system faces to be designed (which I like but not enough to use on my desktop). And Firefox has its own core font family (Fira), for example, that it can use in its own products as an alternate (I think it was designed for the late not-much-lamented Firefox OS)