v5.2.1

Nov 25, 2021

A big thanks to the 7 contributors who made this release possible. Here are some highlights ✨:

This is an early release to fix export 'useId' (imported as 'React') was not found in 'react' when bundling code depending on MUI Core.

• ​[AppBar][docs] Add a fully responsive demo to docs (#29829) @karakib2k18
• ​[core] Fix PR run detection in test_bundle_size_monitor (#29879) @eps1lon
• ​[core] Move bundle size monitoring to CircleCI (#29876) @eps1lon
• ​[docs] Add keys to Responsive AppBar demo (#29884) @mbrookes
• ​[docs] MUI's 2021 Developer survey (#29765) @newguy-123
• ​[docs] Smoother image loading UX (#29858) @oliviertassinari
• ​[Select] Fix select display value with React Nodes (#29836) @kegi
• ​[system] Add experimental_sx utility (#29833) @mnajdova
• ​[test] Ignore "detected multiple renderers" warning for now (#29854) @eps1lon
• ​[useMediaQuery][utils] Remove usage of React 18 APIs (#29870) @eps1lon

All contributors of this release in alphabetical order: @eps1lon, @karakib2k18, @kegi, @mbrookes, @mnajdova, @newguy-123, @oliviertassinari