The major browser vendors are of course members, and participate - and the W3C does a lot more than HTML - but their implementations track WHATWG. As for indiv

The major browser vendors are of course members, and participate - and the W3C does a lot more than HTML - but their implementations track WHATWG. As for individual members, the differences in contribution process between the organisations renders this largely irrelevant. WHATWG membership affords the right to submit proposals and ideas but not to participate in decision-making, which is up to (usually sole) editors, who represent large companies (much larger than most W3C members).