I've been hearing about Neovim; how does it differ from Vim? All the points on the homepage are just architectural changes 'under the hood'. As a user, what's the difference for me?
Just like the neovim homepage describes, neovim's objective is to pave the way for a better & more openly community driven open source project.
The architectural changes not only will bring more stability & improve performance to vim but make the code a lot more maintainable and bring the entry barrier slightly down for anyone who is interested to contribute.
One of the key changes also includes the core feature of access to executing jobs / tasks asynchronously in vim, which has been one of the most requested feature of vim since a long time. This can help improve performance of vim even further especially because vim will not have to block while a background job is doing something.
As a vim user, not much might change besides the fact that neovim should grow as a software much faster (fix issues, add features) as compared to stock vim and that it will have much better performance in the long run.
Edit (10 June, 2020):
I think I missed mentioning one key aspect that differentiates VIM from NeoVIM as an open source software.
The underlying problem (whether or not this is a problem is subjective) with VIM has been that Bram Moolenar, the core contributor is the Gate Keeper and to some extent the bottleneck that prevents changes / fixes / new ideas from other developers making into VIM at a fast pace.
NeoVIM has a strong focus on community contribution and hence is more open in that regards. Also helps that there are several core contributors, not just one.
One interesting side-effect of having NeoVIM is that since it directly competes with VIM, it has resulted in Bram be more open to bringing radical innovations to VIM, which in the absense of NeoVIM he would not have. Things like background jobs, popup windows (floating windows) / text properties, inline terminal, etc are examples of ideas that have been added to VIM because they were saught out features that were added to NeoVIM, even though there has been demand for many of these features since long.
I'm specifically addressing:
Why should I care? As a user, what's the difference for me?
The thing I am most excited about as a Vim user are the new kinds of plugins, integrations, and interfaces that will be enabled by the changes under Neovim's hood.
As time goes by you will begin to see really impressive plugins and programs that work with Neovim but not Vim. There's a list of Neovim-specific plugins: here in neovim's github.
I don't know how up-to-date it is, but I am excited to see it grow as we get more tools to make coding more efficient and enjoyable.
My own favorite addition Neovim brings to the table is terminal mode. You can now split your Neovim window and have a terminal emulator running on one side and be editing a file on the other side! I suppose you could even run Neovim inside of itself now, just in case you really wanted to do that.
Having asynchronous plugins is also going to be extremely useful soon; this means we're finally able to have really good code completion, after only 40 years of waiting!
Neovim also has better mouse support than Vim does.
Two points that are not yet addressed by other answers and might be interesting for a user, even or especially new users without a (or with a small) config file:
- NeoVim does not try to be Vi compatible by default. They changed many default values for the settings and are actively discussing such changes: #2676, #6289
- It can be embedded in another process (remember netbeans integration?) and has many different GUIs so MacVim is no longer the fanciest GUI you can find for your