What's new

Here’s the story of BUI so far, in plain words: what the first release gave you, and what’s waiting in the next one. For every detail, read the full CHANGELOG.md; it follows Keep a Changelog, and versions follow Semantic Versioning.

Coming in the next release

These changes are on main and listed under Unreleased in the changelog.

Closer to Blender 5.x

The biggest theme: BUI now looks and feels even more like the real thing.

• Text rendered like Blender’s. BUI vendors FreeType 2.13.3 and renders text as Blender’s BLF does: light hinting, Blender’s gamma, Inter’s optical size, true bold and Blender’s text shadows. Text and fonts explains it.
• Blender’s own icons. All 781 of Blender’s SVG icons, rasterized with Blender’s nanosvg, in their theme colors.
• The Blender 5.x theme, ported from userdef_default_theme.c.
• Panels, the properties navigation bar and many small widget details ported from Blender, down to the checkmark’s shape.
• Number fields and sliders drag exactly as in Blender: per-pixel steps, Blender’s Ctrl-snapping rules, limits, the drag threshold, and Esc to cancel. See Blender’s widgets.

New components and tools

• The node editor (NodeEditor and Node), ported from Blender’s space_node: nodes, sockets, bezier links, box select, cutting links and Blender’s dot grid.
• Editor areas, sidebars and middle- and right-button input for building editor-style tools.
• Blender’s File Browser, ported from space_file, with bookmarks, recent folders, sorting and Blender’s keymap. tkinter.filedialog and QFileDialog now show it; BUI_FILEDIALOG=native brings back the system dialogs.

Native windows on Linux

A native X11 window host, with the same API as on Windows. Wayland sessions run it through XWayland. The C libraries and the Python module now build and pass their tests on Linux.

JavaScript and React

• @blender-ui/native 0.2.0: BUI from Node.js and Bun in native windows, with a DOM-like API and signals. BUI runs on its own UI thread, and only changes cross over.
• @blender-ui/react 0.1.0: a React 19.3 renderer whose hooks (useState, useMemo, useEffect …) are backed by signals. A conformance suite checks each hook against React’s own.
• bui build: standalone executables of about 5 MB with an embedded QuickJS engine, or a Bun executable with --bun.

Rust

• Components and hooks in zopra, React or Leptos style: #[component], use_state, signals, Memo, Effect and context.
• rsx! and view! markup, with Tailwind classes as bare attributes and “did you mean” compile errors for typos.
• Modern CSS: calc() everywhere, every CSS math function, custom properties, CSS Color 4 and 5, Selectors Level 4, @layer, @container, @font-face and more. Layout moved to taffy 0.15.
• Tailwind CSS v4, compiled on first use.

Rendering

• The GPU renderer on Direct3D 11, opt-in, drawing the same pixels as the CPU raster.
• Slug GPU text, from glyph outlines, switchable with BUI_SLUG.
• Inter embedded as the default face everywhere, with the portable text engine now the default on Windows too.
• Parallel canvas rasterisation on Windows, and many speed-ups across the kit and the Rust crate. For example, a tkinter canvas with 2,000 items and one moving went from 9.4 to 0.08 ms of render time per frame.

Not in the changelog yet

Some work on main is described in the README but doesn’t have a changelog entry yet: Dear ImGui on BUI, the OpenGL 3.3 GPU renderer on Linux, the macOS Cocoa window host, and Blender’s string search and expression evaluator.

Fixed

• GPU text read an environment variable on every text run, which pushed the GPU raster from 1.6 to 9.4 ms per frame at 3,000 cells. It now reads it once.
• In Rust, cx.notify() inside WindowHandle::update didn’t re-render that window.

0.1.0: the first release

The first release of blenderui on PyPI brought the foundations:

• The C kit: Blender’s UI as a C runtime, with the node tree, Tk’s packer and gridder, Blender’s interaction (hover, drag grabs, the continuous cursor, menus, tooltips), widget drawing ported from interface_widgets.cc, damage-driven rendering, undo and redo, animation, text areas, canvases and scroll views.
• A native Windows host, DPI-aware, with vsync’d animation. Other platforms used a Tk window.
• tkinter syntax: all 7,846 public names of tkinter and ttk, plus the dialogs and helper modules. Existing apps run unchanged with blenderui-tk app.py.
• Qt syntax: a subset of Qt’s widgets, layouts, signals, QPainter, menus and timers.
• 45 Blender components, from panels and sliders to pie menus, the color picker and editors.
• Packaging as blenderui, with import blenderui as an alias of bui.

Next steps