New comment by atweiden on void-packages repository

https://github.com/void-linux/void-packages/issues/36164#issuecomment-1080035784

Comment:
> @atweiden you'll find that neomutt deliberately broke compat and suggested it no longer be the same.
> 
> For neomutt, this was the answer.
> 
> For neovim it's not.

Try opening a file with `vim`, closing it, then opening the same file with `nvim` (or vice versa). You might be surprised to see an error message pop up:

```
E824: Incompatible undo file: ....
```

That’s because Neovim has broken Vim compatibility in several subtle ways for a long time now.

Here’s another example: Vim uses [viminfo](http://vimdoc.sourceforge.net/htmldoc/starting.html#viminfo) files, but Neovim uses an incompatible [ShaDa](https://neovim.io/doc/user/starting.html#shada-file) file. Hence, when attempting to share the same config between `vim` and `nvim`, you have to implement a workaround:

```vim
if !has('nvim')
  set viminfofile=$VIMPATH/viminfo
  if filereadable(&viminfofile)
    rviminfo
  endif
else
  if filereadable($XDG_DATA_HOME . '/nvim/shada/main.shada')
    rshada
  endif
endif
```

Otherwise you’ll get an error on startup.

- Neovim uses subtly different highlight groups in certain cases, e.g. `WhiteSpace` instead of Vim’s `SpecialKey` for rendering indentation

- `nvim` severely alters your terminal cursor by default, whereas `vim` doesn’t

- Neovim plugins are increasingly written in pure Lua, which is not the case with Vim

Bram Moolenaar has been merging features and bug fixes to upstream Vim at a considerably faster pace than Neovim can integrate them downstream for the last several years consecutively. This isn’t meant to throw any shade on Neovim — it’s good to see so much third party development happening on Neovim in Lua. But they’re divergent software projects in several respects.

There was a limited period of time c. 2016 when Neovim was still fighting to become “Vim” due to perceived inaction on Bram’s part. That didn’t happen, but people who don’t heavily use Vim or Neovim may not be aware of such things.