Selenium 4.3 will only support W3C compliant WebDriver syntax
Updating your locators for changes in the Python bindings in Selenium 4
Support for IE Mode in Edge with IEDriver
There’s more to Selenium 4 than just the server
Introducing how Selenium 4 handles authentication
Summary of the Selenium survey that was collected
Browser Testing and Tools WG Meeting @ TPAC 2020
As mentioned in Simon’s Going Atomic: Why? and Going Atomic: How, part of the merging of Selenium and WebDriver is to share common code between the two.