Techniques des Mathématiques ( Niveau BEP, BAC ; Master, DESS)

Hello, the community and at the beginning I would like to ask you what web portals are most often hosted in your browsers and what are your preferences in this "matter"?

For example, I visit a news aggregator from various portals https://xmc.pl>Blogi Edukacyjne what distinguishes it from other websites of this type? Check it out for yourself

I look forward to an interesting and substantive discussion :)