A website that I recently came across is numerical.recipes . For those with computing related (especially scientific computing) the Numerical Recipes series of books and associated code resources from Cambridge Univ. Press are well known (two copies sat on my bookshelf until I retired, one in Fortran and one in C++). Anyway, it turns out they were one of the first few thousand sites on internet (well in .com at least) with the domain name NR.com. They sold it to a domain investor in China (I am not sure the price, but I assume it was at least 6 figures), and rebranded themselves appropriately as Numberical.recipes.
Export Development Canada (a Canadian government sponsored site to support international trade opportunities) use a .trade (as well as of course their .ca main site):