Is timsort general-purpose or Python-specific?

Yes, it makes quite a bit of sense to use timsort outside of CPython, in specific, or Python, in general.

There is currently an effort underway to replace Java's "modified merge sort" with timsort, and the initial results are quite positive.

It doesn't look particularly familiar, but "smart" mergesorts are pretty common out in the wide world of software.

As for whether it makes sense, that depends on what you're sorting, and the relative cost of comparisons vs. memory allocation. A sort that requires up to 2*N bytes of extra memory isn't going to be a good choice in a memory-constrained environment.

The algorithm is pretty generic, but the benefits are rather Python-specific. Unlike most sorting routines, what Python's list.sort (which is what uses timsort) cares about is avoiding unnecessary comparisons, because generally comparisons are a lot more expensive than swapping items (which is always just a set of pointer copies) or even allocating some extra memory (because it's always just an array of pointers, and the overhead is small compared to the average overhead in any Python operation.)

If you're under similar constraints, then it may be suitable. I've yet to see any other case where comparisons are really that expensive, though :-)