user: What is Version/Revision Milestones and how is it used in Blender Python scripting?

assistant: The start!

- **1.00 – January 1994:** Blender
  [in development](https://code.blender.org/2013/12/how-blender-started-twenty-years-ago/)
  at animation studio NeoGeo.
- **1.23 – January 1998:** SGI version published on the web, IrisGL.
- **1.30 – April 1998:** Linux and FreeBSD version, port to OpenGL and X11.
- **1.3x – June 1998:** NaN founded.
- **1.4x – September 1998:** Sun and Linux Alpha version released.
- **1.50 – November 1998:** First Manual published.
- **1.60 – April 1999:** C-key (new features behind a lock, $95), Windows version released.
- **1.6x – June 1999:** BeOS and PPC version released.
- **1.80 – June 2000:** End of C-key, Blender full freeware again.
- **2.00 – August 2000:** Interactive 3D and real-time engine.
- **2.10 – December 2000:** New engine, physics, and Python.
- **2.20 – August 2001:** Character animation system.
- **2.21 – October 2001:** Blender Publisher launch.
- **2.2x – December 2001:** macOS version.

Blender goes Open Source

13 October 2002:
:   **Blender goes Open Source, 1st Blender Conference.**

2.25 – October 2002:
:   [Blender Publisher](https://download.blender.org/release/Publisher2.25/) becomes freely available,
    and the experimental tree of Blender is created, a coder’s playground.

2.26 – February 2003:
:   The first truly open source Blender release.

2.27 – May 2003:
:   The second open source Blender release.

2.28x – July 2003:
:   First of the 2.28x series.

[2.30](https://archive.blender.org/www/development/release-logs/blender-230/) – October 2003:
:   Preview release of the 2.3x UI makeover presented at the 2nd Blender Conference.

[2.31](https://archive.blender.org/www/development/release-logs/blender-231/) – December 2003:
:   Upgrade to stable 2.3x UI project.

[2.32](https://archive.blender.org/www/development/release-logs/blender-232/) – January 2004:
:   A major overhaul of internal rendering capabilities.

[2.33](https://archive.blender.org/www/development/release-logs/blender-233/) – April 2004:
:   Game Engine returns, ambient occlusion, new procedural textures.

[2.34](https://archive.blender.org/www/development/release-logs/blender-234/) – August 2004:
:   Particle interactions, LSCM UV mapping, functional YafRay integration, weighted creases in subdivision surfaces,
    ramp shaders, full OSA, and many (many) more.

[2.35](https://archive.blender.org/www/development/release-logs/blender-235a/) – November 2004:
:   Another version full of improvements: object hooks, curve deforms and curve tapers,
    particle duplicators and much more.

[2.36](https://archive.blender.org/www/development/release-logs/blender-236/) – December 2004:
:   A stabilization version, much work behind the scenes, normal and displacement mapping improvements.

[2.37](https://archive.blender.org/www/development/release-logs/blender-237a/) – June 2005:
:   Transformation tools and widgets, soft bodies, force fields, deflections,
    incremental subdivision surfaces, transparent shadows, and multi-threaded rendering.

[2.40](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.40) – December 2005:
:   Full rework of armature system, shape keys, fur with particles, fluids, and rigid bodies.

[2.41](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.41) – January 2006:
:   Lots of fixes, and some Game Engine features.

[2.42](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.42) – July 2006:
:   The nodes release, Array modifier, vector blur, new physics engine, rendering, lip sync, and many other features.
    This was the release following [Project Orange](https://orange.blender.org/).

[2.43](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.43) – February 2007:
:   Multiresolution meshes, multi-layer UV textures, multi-layer images and multi-pass rendering and baking, sculpting,
    retopology, multiple additional mattes, distort and filter nodes, modeling and animation improvements, better
    painting with multiple brushes, fluid particles, proxy objects, Sequencer rewrite, and post-production UV
    texturing.

[2.44](https://archive.blender.org/www/development/release-logs/blender-244/index.html) – May 2007:
:   The big news, in addition to two new modifiers and re-awakening the 64-bit OS support, was the addition of
    subsurface scattering, which simulates light scattering beneath the surface of organic and soft objects.

[2.45](https://archive.blender.org/www/development/release-logs/blender-245/index.html) – September 2007:
:   Serious bug fixes, with some performance issues addressed.

[2.46](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.46) – May 2008:
:   The Peach release was the result of a huge effort of over 70 developers providing enhancements to provide hair and
    fur, a new particle system, enhanced image browsing, cloth, a seamless and non-intrusive physics cache, rendering
    improvements in reflections, AO, and render baking, a Mesh Deform modifier for muscles and such, better animation
    support via armature tools and drawing, skinning, constraints and a colorful Action Editor, and much more. It
    contained the results of [Project Peach](https://peach.blender.org/).

[2.47](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.47) – August 2008:
:   Bugfix release.

[2.48](https://archive.blender.org/www/development/release-logs/blender-248/index.html) – October 2008:
:   The Apricot release, cool GLSL shaders, lights and GE improvements, snap, sky simulator, Shrinkwrap modifier, and
    Python editing improvements. This contained the results of [Project Apricot](https://apricot.blender.org/).

[2.49](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.49) – June 2009:
:   Node-based textures, armature sketching (called Etch-a-Ton), Boolean mesh operation improvements, JPEG2000 support,
    projection painting for direct transfer of images to models, and a significant Python script catalog. GE
    enhancements included video textures, where you can play movies in-game, upgrades to the Bullet physics engine,
    dome (fisheye) rendering, and more API GE calls made available.

Blender 2.5x – The Recode!

[2.5x](https://www.blender.org/download/releases/#25-series-2009-2011) – From 2009 to August 2011:
:   This series released four [pre-version](https://archive.blender.org/www/development/release-logs/blender-256-beta) (from Alpha 0 in November 2009 to
    Beta in July 2010) and three stable versions (from 2.57 - April 2011 to 2.59 - August 2011). It was one of the most
    important development projects, with a total refactor of the software with new functions, redesign of the internal
    window manager and event/tool/data handling system, and new Python API. The final version of this project was
    Blender 2.59 in August 2011.

Blender 2.6x to 2.7x – Improvements & Stabilizing

[2.60](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.60) – October 2011:
:   Internationalization of the UI, improvements in the animation system and the GE, vertex weight groups modifiers, 3D
    audio and video, and bug fixes.

[2.61](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.61) – December 2011:
:   The Cycles renderer was added to the trunk, the camera tracker was added, dynamic paint for modifying textures with
    mesh contact/approximation, the Ocean modifier to simulate ocean and foam, new add-ons, bug fixes, and more
    extensions added for the Python API.

[2.62](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.62) – February 2012:
:   The [Carve library](https://code.google.com/archive/p/carve/) was added to improve Boolean operations, support
    for object tracking was added, the Remesh modifier was added, many improvements in the GE, matrices and vectors in
    the Python API were improved, plus new add-ons, and many bug fixes.

[2.63](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.63) – April 2012:
:   Bmesh was merged with the trunk, with full support for n-sided polygons, sculpt hiding, a panoramic camera for
    Cycles, mirror ball environment textures and float precision textures, render layer mask layers, ambient occlusion
    and viewport display of background images and render layers. New import and export add-ons were added, and 150 bug
    fixes.

[2.64](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.64) – October 2012:
:   A mask editor was added, along with an improved motion tracker, OpenColorIO, Cycles improvements, Sequencer
    improvements, better mesh tools (Inset and Bevel were improved), new keying nodes, sculpt masking,
    COLLADA improvements, a new Skin modifier, a new compositing nodes backend, and the fixing of many bugs.

[2.65](https://archive.blender.org/wiki/2015/index.php/Dev:Ref/Release_Notes/2.65) – December 2012:
:   Fire and smoke improvements, anisotropic shader for Cycles, modifier improvements, the Bevel tool now includes
    rounding, new add-ons, and over 200 bug fixes.

[2.66](https://www.blender.org/download/releases/2-66) – February 2013:
:   Dynamic topology, rigid body simulation, improvements in UI and usability (including retina display support),
    Cycles now supports hair, the Bevel tool now supports individual vertex beveling, new [Mesh Cache](../../modeling/modifiers/modify/mesh_cache.xhtml) modifier and the new [UV Warp](../../modeling/modifiers/modify/uv_warp.xhtml)
    modifier, new SPH particle fluid solver. More than 250 bug fixes.

[2.67](https://www.blender.org/download/releases/2-67) – May 2013:
:   Freestyle was added, paint system improvements, subsurface scattering for Cycles, Ceres library in the motion
    tracker, new custom Python nodes, new mesh modeling tools, better support for UTF-8 text and improvements in Text
    editors, new add-ons for 3D printing, over 260 bug fixes.

[2.68](https://www.blender.org/download/releases/2-68) – July 2013:
:   New and improved modeling tools, three new Cycles nodes, big improvements in the motion tracker, Python scripts and
    drivers are disabled by default when loading files for security reasons, and over 280 bug fixes.

[2.69](https://www.blender.org/download/releases/2-69) – October 2013:
:   Even more modeling tools, Cycles improved in many areas, plane tracking is added to the motion tracker, better
    support for FBX import/export, and over 270 bugs fixed.

[2.70](https://www.blender.org/download/releases/2-70) – March 2014:
:   Cycles gets basic volumetric support on the CPU, more improvements to the motion tracker, two new modeling
    modifiers, some UI consistency improvements, and more than 560 bug fixes.

[2.71](https://www.blender.org/download/releases/2-71) – June 2014:
:   Deformation motion blur and fire/smoke support is added to Cycles, UI pop-ups are now draggable. There are
    performance optimizations for sculpting mode, new interpolation types for animation, many improvements to the GE,
    and over 400 bug fixes.

[2.72](https://www.blender.org/download/releases/2-72) – October 2014:
:   Cycles gets volume and SSS support on the GPU, pie menus are added and tooltips greatly improved, the Intersection
    modeling tool is added, new Sun Beam node for the Compositor, Freestyle now works with Cycles, texture painting
    workflow is improved, and more than 220 bug fixes.

[2.73](https://www.blender.org/download/releases/2-73/) – January 2015:
:   Cycles gets improved volumetric support, major upgrade to Grease Pencil, Windows gets Input Method Editors (IMEs)
    and general improvements to painting, Freestyle, Sequencer and add-ons.

[2.74](https://www.blender.org/download/releases/2-74/) – March 2015:
:   Support for custom normals, viewport compositing and improvements to hair dynamics.

[2.75](https://www.blender.org/download/releases/2-75/) – July 2015:
:   Integrated stereo/multi-view pipeline, Smooth Corrective modifier and new developmental dependency graph.

[2.76](https://www.blender.org/download/releases/2-76/) – November 2015:
:   Pixar OpenSubdiv support, Viewport and File Browser performance boost,
    node auto-offset, and a text effect strip for the Sequencer.

[2.77](https://www.blender.org/download/releases/2-77/) – March 2016:
:   OpenVDB support for caching of smoke/volumetric simulations, improved Cycles subsurface scattering, Grease Pencil
    stroke sculpting and improved workflow, and reworked library handling to manage missing and deleted data-blocks.

[2.78](https://www.blender.org/download/releases/2-78/) – September 2016:
:   Cycles support for spherical stereo images for VR, Grease Pencil works more similar to other 2D drawing software,
    Alembic import and export support, and improvements to Bendy Bones for easier and simpler rigging.

[2.79](https://www.blender.org/download/releases/2-79/) – September 2017:
:   New Cycles features: Denoising, Shadow catcher, and new Principled shader. Other improvements were made to Grease
    Pencil and Alembic. Support was also added for application templates.

Blender 2.8 – Revamped UI

[2.80](https://www.blender.org/download/releases/2-80) – July 2019:
:   A totally redesigned UI for easier navigation; improved viewport, gizmos, and tools. With EEVEE a new physically
    based real-time render engine was created. The Grease Pencil got a big overhaul and is now a full 2D drawing and
    animation system. Replacing the old layers, collections are a powerful way to organize objects. Other improvements:
    Cycles, Modeling, Animation, Import/Export, Dependency Graph.

[2.81](https://www.blender.org/download/releases/2-81/) – November 2019:
:   Revamped sculpting tools, Cycles OptiX accelerated rendering, denoising, many EEVEE improvements, library
    overrides, UI improvements and much more.

[2.82](https://www.blender.org/download/releases/2-82/) – February 2020:
:   UDIM and USD support, Mantaflow for fluids and smoke simulation, AI denoising, Grease Pencil improvements, and much
    more.

[2.83 LTS](https://www.blender.org/download/releases/2-83/) – June 2020:
:   3D Viewport virtual reality scene inspection, new volume object type, Cycles adaptive sampling, Cycles viewport
    denoising, sculpting improvements, and much more. **First LTS release intended to support studio and long lifecycle
    project use.**

Blender 2.9 – Refining 2.8

[2.90](https://www.blender.org/download/releases/2-90/) – August 2020:
:   Improved sky texture, EEVEE motion blur, sculpting improvements, revamped modifier UI, improved modeling tools, and
    faster motion blur in Cycles.

[2.91](https://www.blender.org/download/releases/2-91/) – November 2020:
:   Outliner improvements, property search, improved mesh Boolean operations, animation curves, volume object and
    display improvements, and more refined sculpting tools.

[2.92](https://www.blender.org/download/releases/2-92/) – February 2021:
:   Geometry nodes, primitive add tool, sculpting improvements, Grease Pencil curve editing, Cycles Color Attribute
    baking, APIC fluid simulations, Video Sequencer improvements, and much more.

[2.93 LTS](https://www.blender.org/download/releases/2-93/) – June 2021:
:   New geometry nodes, sculpting improvements, Grease Pencil Line Art modifier along with other improvements, an
    improved DOF for the EEVEE render engine, redesigned Cryptomatte workflow, and more. **LTS
    release for the 2.9 series.**

Blender 3.0 – Optimizing Performance

[3.0](https://www.blender.org/download/releases/3-0/) – December 2021
:   Asset Browser added, Cycles X, EEVEE Attributes, New geometry nodes, animation update, Grease Pencil Line Art
    improvements, pose library, Open Image Denoising 2-8x faster, additional support for AMD on linux.

[3.1](https://www.blender.org/download/releases/3-1/) – March 2022
:   Major point clouds improvements, Cycles Apple Metal GPU support, Subdivision GPU support, image editor handles
    larger images, Major performance gains for geometry nodes, context aware search for geometry nodes.

[3.2](https://www.blender.org/download/releases/3-2/) – June 2022
:   Light groups for Cycles, true Shadow caustics, volume motion blur, GLTF improvements, AMD GPU Rendering on Linux,
    painting in sculpt mode, WEBp image support.

[3.3 LTS](https://www.blender.org/download/releases/3-3/) – September 2022
:   New hair object, procedural UV nodes, Line Art shadow and contour, Intel GPU rendering support via oneAPI, and
    improvements to library overrides. **First LTS release of the 3.0 series.**

[3.4](https://www.blender.org/download/releases/3-4/) – December 2022
:   Cycles path guiding, sculpting auto masking improvements, even more geometry nodes, UV Editing improvements and
    Wayland support on Linux.

[3.5](https://www.blender.org/download/releases/3-5/) – March 2023
:   New generative hair assets, vector displacement maps for sculpting, viewport compositor, and Cycle’s light trees.

[3.6 LTS](https://www.blender.org/download/releases/3-6/) – June 2023
:   Simulation nodes added to Geometry Nodes, Cycles hardware ray-tracing for AMD and Intel, UV island packing, asset
    bundle from Blender Studio and community artists included, new retopology overlay. **Final LTS of the 3.0 series.**

Blender 4.0 – A Major Leap For Rendering, Creating Tools, and More

[4.0](https://www.blender.org/download/releases/4-0/) – November 2023
:   A new Principled BSDF shader with coat and sheen layers, AgX view transform, Voronoi Texture fractal noise, light
    linking for selective lighting, run Geometry Nodes as Node Tools, snapping improvements including Snap Base, menu
    and modifier type-to-search, new [Inter](https://rsms.me/inter/) typeface, streamlined keymap, bone collections,
    Hydra Storm USD renderer, larger asset library, alignment to the [VFX Reference Platform 2023](https://vfxplatform.com/).

[4.1](https://www.blender.org/downlo