From next month, Google and YouTube will prohibit ads on content that refers to the climate crisis as a scam or denies the impact of human activity and rising emissions.
Musk had earlier threatened to move Tesla to Texas or Nevada after falling out with local California officials over Covid-19 regulations.
Duolingo founder and chief executive Luis von Ahn is aiming to lure children away from TikTok and Instagram with the popular language-learning app's new mathematics version.
Facebook has apologised after it stopped working for users around the world for several hours on Monday.
WhatsApp and Instagram - which are owned by the company - were also down.
A report from Google Cloud has highlighted how researchers in many fields are increasingly using cloud-based online collaboration and communication tools, AI and Machine Learning, following the disruption caused by the pandemic.