I see that both
nlinum are actively maintained: one is built-in, another recently had a release.
With older Emacs version,
linum used to be slow with a lot of folding in a buffer (e.g. in Org mode, and with
hs-minor-mode in various source code modes). So I switched to
Currently (on Emacs 15 and 26) I see that
linum is sort of fast again, though maybe not always as smooth as
Is there a reason why I should stick to one of them from maintainability POV? That is, does one of them obsolete, or is going to obsolete, another?