The Jordan-Holder theorem says that any chain of subobjects of a finite length object can be refined to a composition series, and that any composition series has the same length.

This theorem holds for any abelian category, and a notable example is the case of modules over some ring. While I do not need an example of the usefulness of JH theorem in the context of modules, I would like to ask:

What are applications of the JH theorem in a general abelian category, which is not (or not easily proven to be) a category of modules?

[originally asked on mathstackexchange]