- A new [`sleep` command](https://github.com/nushell/nushell/pull/2381) (LhKipp)
- Improvements to `ls` and [hidden files](https://github.com/nushell/nushell/pull/2379) (mattclarke)
- `sort-by` errors [now point to mismatched types](https://github.com/nushell/nushell/pull/2366) (luccasmmg)
- `str` subcommands for [various capitalizations](https://github.com/nushell/nushell/pull/2360) (rrichardson)
- Time units are now [more readable](https://github.com/nushell/nushell/pull/2356) (mattclarke)
- Exit scripts from per-directory environments are now [run in the original directory](https://github.com/nushell/nushell/pull/2352) (samhedin)
- We've also got a [Portuguese translation of the contributor book(!!)](https://github.com/nushell/contributor-book/pull/29) (vpperego)
- Improved [RHEL installation instructions](https://github.com/nushell/book/pull/126) (arnaldo2792)

## More cleanup and improvements (gillespiecd, sophiajt, Marcoleni, andrasio, dmeijboom, thegedge, jzaefferer, ryuichi1208, JosephTLyons)

Cleanups in math commands, extra bits of command help, reformatting of the command list, better email samples, cleaned up spans in pipelines, fix to `header` command with mismatched columns, cleanup of dependency usage, cleaned up display config, added crossreferences in command help, subcommands are now sorted before being listed, some dockerfile improvements, nu-cli now has nu-data split off from it, column count now won't break on empty tables, wasm is now tested on CI, improvements to `histogram` and `count`,

## Breaking changes

### Starship is now external

To help Nu focus a bit more on the core capabilities, and to free up it to update separate from Nu, Starship is now external. Once you install Starship, you can set your prompt to use starship using:

```
> config set prompt `echo $(starship prompt)`
```

You can also set Nu to use other prompts as well. For example, if you like powerline, you can also use this:

```
> config set prompt `echo $(powerline shell left)`
```

### No more auto-pivot by default

Based on feedback from users, we've now disabled any auto-pivoting of tables by default. You can still re-enable this behavior in your config, but we will no longer rotate any tables without being explicitly asked.

```
# To only rotate large tables:
> config set pivot_mode auto

# To always rotate a single row to be vertical:
> config set pivot_mode always
```

### Time units are now renamed

To make it easier, and more readable, to work with a variety of units in the future, we've renamed the time units.

Instead of `1s`, you'll now use `1sec`. Most units for time now follow 3 letters instead of a single letter. You can read more about the [full change in the PR](https://github.com/nushell/nushell/pull/2356).

### Header colors

With the new theming support, `header_color`, `header_bold`, and `header_align` have moved into the `[color_config]` section, and out of the root level, of the `config.toml` file.

### Simplified default build

While not technically a breaking change, it's worth a mention that starting with 0.19, you don't need to use `--features=stable` to get most of Nu's features. We've folded most of the common ones into the default install. For all the bells and whistles, now use `--features=extra`, which includes additional functionality not part of the original `stable` release.

# Looking forward

With 0.19, we see the first deeper changes to the completion engine since Nu was first released. These will grow to allow custom completions for commands, and we're looking forward to making these features available.

The new table literal also takes a step in the direction of data frame support in the future, a powerful feature popularized by pandas, R and other data processing libraries and languages. With it, we hope Nu will continue to grow to having a richer, more nuanced, view of data over time.