ESE was formerly known as Joint Engine Technology (JET) Blue. It was originally developed by Microsoft to replace the JET Red database engine in Access in the 1990s.
Microsoft open-sourced the project in 2021.
https://docs.microsoft.com/en-us/windows/win32/extensible-storage-engine/extensible-storage-engine
https://github.com/microsoft/Extensible-Storage-Engine
Microsoft
1994
JET Blue