"Everybody who runs a Web site knows we're not assured of compatibility, and we could end up with a split"

This quote by Tim Berners-Lee is referring to the fact that the internet is continuously changing and evolving. As web designers, we are not ensured that our websites will be compatible with the current innovations and requirements. This indicates that if we do not keep up with the changes, our websites could end up being outdated and incompatible with the current web requirements. This might lead to a "split" in the web, where some sites work with the latest standards and others are not. This could lead to a circumstance where some sites are not available to particular users, or where specific functions are not available on particular websites. It is important for web developers to stay up to date with the most recent technologies and standards in order to make sure that their sites remain compatible and accessible to all users.