Added
- Add support for circular networks in `sankey` traces [[3406](https://github.com/plotly/plotly.js/pull/3406), [#3535](https://github.com/plotly/plotly.js/pull/3535), [#3564](https://github.com/plotly/plotly.js/pull/3564)]
- Add matching axes behavior to cartesian axes via new axis attribute and
new splom attribute dimensions attribute `matches` [[3506](https://github.com/plotly/plotly.js/pull/3506), [#3565](https://github.com/plotly/plotly.js/pull/3565)]
- Add attributes `alignmentgroup` and `offsetgroup` to `bar`, `histogram`, `box`
and `violin` traces to make cross-trace positioning easier [[3529](https://github.com/plotly/plotly.js/pull/3529)]
- Add support for orthographic projections in gl3d subplots via new attribute
`scene.camera.projection.type` [[3550](https://github.com/plotly/plotly.js/pull/3550)]
- Add `cmid` and `zmid` colorscale attributes to pick the middle of the color
range during the auto-colorscale computations [[3549](https://github.com/plotly/plotly.js/pull/3549)]
- Add support for `sankey` grouping via new attribute `groups` [[3556](https://github.com/plotly/plotly.js/pull/3556)]
- Add support for `sankey` concentration `colorscales` [[3501](https://github.com/plotly/plotly.js/pull/3501)]
- Add support for `hovertemplate` for all `gl3d` traces, `contour`,
`heatmap`, `histogram*`, `parcats`, `scattercarpet` and `splom` traces [[3530](https://github.com/plotly/plotly.js/pull/3530)]
- Add `hovertext` attribute to all traces that support hover 'text',
for consistency with traces that already have an `hovertext` attribute [[3553](https://github.com/plotly/plotly.js/pull/3553)]
- Add support for layout `meta` templating in trace `name`,
`rangeselector`, `updatemenus` and `sliders` labels as well as
within `hovertemplate` [[3548](https://github.com/plotly/plotly.js/pull/3548)]
- Add support for `opacity` to `isosurface` traces [[3545](https://github.com/plotly/plotly.js/pull/3545)]
- Add `mapbox.layers` attributes: `minzoom`, `maxzoom`, `line.dash` and `symbol.placement` [[3399](https://github.com/plotly/plotly.js/pull/3399)]
Changed
- More consistency pass down WebGL pixel ratio to gl3d renderers,
this leads to better axis line and error bar rendering on some hardwares [[3573](https://github.com/plotly/plotly.js/pull/3573)]
- Performance boost for `isosurface` trace generation [[3521](https://github.com/plotly/plotly.js/pull/3521)]
- Export template string regex of `Lib` [[3548](https://github.com/plotly/plotly.js/pull/3548)]
- Do no cluster points in `scattergl` trace with less than 1e5 data pts,
this fixes reported "missing data points" scenarios [[3578](https://github.com/plotly/plotly.js/pull/3578)]
Fixed
- Fix selection outline clearing during cartesian axis-range relayout calls
(bug introduced in 1.42.0) [[3577](https://github.com/plotly/plotly.js/pull/3577)]
- Fix modebar interactions on graphs with `scatter3d` traces with
marker colorscales (bug introduced in 1.44.0) [[3554](https://github.com/plotly/plotly.js/pull/3554)]
- Fix axis `automargin` for superimposed subplots (bug introduced in 1.44.3) [[3566](https://github.com/plotly/plotly.js/pull/3566)]
- Fix polar angular tick labels placement [[3538](https://github.com/plotly/plotly.js/pull/3538)]
- Fix `scattergl` updates after selections for trace with on-graph text [[3575](https://github.com/plotly/plotly.js/pull/3575)]
- Fix `responsive: true` config option for graph with WebGL traces [[3500](https://github.com/plotly/plotly.js/pull/3500)]
- Fix `modebar.bgcolor` for vertical modebars with wrapped buttons [[3500](https://github.com/plotly/plotly.js/pull/3500)]
- Fix `ohlc` and `candlestick` auto-range computations [[3544](https://github.com/plotly/plotly.js/pull/3544)]