The author of mobx, Michel Weststrate, also created something called MST (short for mobx-state-tree), which was a kind of answer to redux.

A direct quote from https://github.com/mobxjs/mobx-state-tree

> mobx-state-tree is a state container that combines the simplicity and ease of mutable data with the traceability of immutable data and the reactiveness and performance of observable data.