https://github.com/mrdoob/three.js/wiki/Migration-Guide#r124--r125
https://github.com/mrdoob/three.js/milestone/38?closed=1

Source

• Global
  • Log a warning when importing multiple instances of the library. #21128, 2a853ac, 87e6d9e (@mrdoob, @Mugen87)
• Color
  • Added .lerpColors(). #21061 (@mrdoob)
  • Fix ReDoS in .setStyle(). #21143 (@yetingli)
• Font
  • Convert to ES6 class. #21050 (@linbingquan)
• Geometry
  • Remove from core. #21031, #21012, #21015, #21022, #21018, #21033, #21038, #21044, #21046, #21077, #21078, #21082, #21116 (@mrdoob, @Mugen87)
• InstancedMesh
  • Honor instanceColor in copy(). #21028 (@Mugen87)
• KeyframeTrack
  • Fix typo in .optimize(). #21071 (@donmccurdy)
• MathUtils
  • Add .pingpong(). #21091 (@marcofugaro)
  • Add .damp() for framerate independent lerping. #21102 (@marcofugaro)
• Matrix4
  • Add .setFromMatrix3(). #20991 (@gkjohnson)
• PMREMGenerator
  • Improve handling of background and clear color. #20983 (@gkjohnson)
  • Make background result independent of premultipliedAlpha setting. #21034 (@gkjohnson)
• Vector4
  • Add multiply(). #21065 (@marcofugaro)
• WebGLExtensions
  • Introduce .init(). #21080 (@Mugen87)
• WebGLRenderer
  • Fix updating some material properties in initMaterial(). #21020, #21043 (@Oletus)
  • Fix getting float render target extensions. #21069, #21073 (@Oletus, @Mugen87)
• WebGLRenderTarget
  • Convert to ES6 class. #21053 (@alexfriesen)
• WebGLTextures
  • Set all pixel storage modes for CubeTexture. #20961 (@11zouzouzou)
• WebXRManager
  • Use async/await in setSession(). #20754 (@Mugen87)
  • Updated WebXR Hand implementation to the new API. #20938 (@cabanier)
  • Update camera's local matrix and transform properties. #19085 (@Mugen87)
  • Reset _currentDepthNear/_currentDepthFar in onSessionEnd(). #21146 (@chpatrick)

Documentation

• Clean up. #21104 (@Mugen87)
• Improved Chinese translation. #20976, #20993, #21025, #21066, #21079 (@puxiao, @jiangxiaoxin, @ilzhi, @linbingquan)
• Improved Korean translation. #20940, #20952 (@hareha)
• Improved Creating Text page. #20817 (@gonnavis)
• Improved DRACOLoader page. #20973 (@gkjohnson)
• Improved GLTFLoader page. #21155 (@donmccurdy)
• Improved Object3D page. #21124 (@Mugen87)
• Improved ObjectLoader page. #20988, #20989 (@cloud9c, @Mugen87)
• Improved OrbitControls page. #21134 (@1993heqiang)
• Improved Vector3 page. #21154 (@j13ag0)
• Add plugins and libraries page. #21010, #21093 (@gkjohnson)
• Refactor geometry browser. #21030 (@Mugen87)
• Added docs for KTX2Loader. #21169 (@elalish)

TypeScript

• Clean up. #21049 (@linbingquan)
• Improved declaration of clone() methods. #20947 (@Tonvey)
• Fix KeyframeTrack constructor types. #20994 (@vickyliin)
• Add loadAsync() typings. #21001 (@mjurczyk)
• Added Curve.computeFrenetFrames(). #21036 (@ycw)
• Improved types for AudioContext. #21048 (@linbingquan)
• Add uuid as a type to Shape. #21058 (@joshuaellis)
• Add userData to SVGResult.paths. #21059 (@joshuaellis)
• Improved Skeleton and SkeletonUtils types. #21051 (@maccesch)
• Added types for XRHandModel and its methods. #21109 (@CodyJasonBennett)
• Fix typings for CurveModifier and TessellateModifier. #21112 (@cgauld)
• The canvas parameter of CanvasTexture now accepts ImageBitmap. #21120 (@AlexandrosGounis)
• Add failIfMajorPerformanceCaveat. #21157 (@Mugen87)

Examples

• Clean up. #20966, #21115, #21158 (@vvanghelue, @takahirox, @Mugen87)
• Replace zip libraries with fflate. #20959, #20965, #20970 (@Mugen87, @101arrowz)
• Refactor webgl_simple_gi. #20996 (@Mugen87)
• Move example code to BufferGeometry. #20999, #21004, #21006, #21005, #21007, #21013, #21021 (@Mugen87)
• Consolidate morph target examples. #20998 (@Mugen87)
• Remove Geometry support from exporters, geometries and modifiers. #21008, #21009, #21026, #21062, #21067, #21060, #21081, #21087, #21090 (@Mugen87, @mrdoob)
• Removed OBJLoader2 and OBJLoader2Parallel. #21014 (@mrdoob)
• Simplified and improved RectAreaLight example. #21016 (@mrdoob)
• Removed FaceNormalsHelper. #21017 (@mrdoob)
• Fix contact shadow example. #21063 (@marcofugaro)
• Use event.code instead of instead of event.keyCode. #21055, #21056 (@felixmariotto)
• Removed SubdivisionModifier. #21072 (@Mugen87)
• Add photosensitive epilepsy warning to webgl_postprocessing_glitch. #20978 (@FrodoLuo)
• Remove useCapture parameter from event listeners. #21101, #21110, #21125 (@marcofugaro)
• Add webgl_loader_gltf_compressed example. #21114, 067cf15 (@zeux, @mrdoob)

• 3DMLoader

  • Improved point cloud and NURBS support. #21095 (@fraguada)

• BasisTextureLoader

  • Update Basis library. #21094 (@donmccurdy)
  • Refactor. #21131, #21144 (@donmccurdy)

• BufferGeometryUtils

  • Added .computeMorphedAttributes(). #21064, #21086, f21ecaf (@SntsDev, @mrdoob)

• CubeTexturePass

  • Clone uniforms and properly configure flipEnvMap. #21130 (@Mugen87)

• FBXLoader

  • Fix transform inheritance, convert back to local. #20932 (@DVLP)

• GLTFLoader

  • Respect file contents length defined in header. #21122 (@gkjohnson)
  • Fixed variants normal map scale. #21148, #21168 (@elalish)

• GLTFExporter

  • Support textures using OffscreenCanvas. #21074 (@TechnologicNick)

• KTX2Loader

  • Fix calculation of level dimensions for NPOT textures. #20888 (@donmccurdy)
  • Improve parsing and transcoding process. #21137 (@donmccurdy)

• Line2

  • Fix missed intersections when segment extends behind camera near plane. #21041 (@gkjohnson)

• LUTPass

  • Improve LUT Sampling. #21040 (@gkjohnson)

• OrbitControls

  • Introduce listenToKeyEvents(). #21054 (@Mugen87)

• RGBMLoader

  • Added new loader. #21145 (@Mugen87)

• TrackballControls

  • Fix middle mouse button. #20990 (@Mugen87)

• USDZExporter

  • Added new class. #21096, 2ceee29 (@mrdoob)

• WebGPURenderer

  • Clean up. #21118 (@Mugen87)
  • Add initial version of a node based material system. #20421 (@sunag)
  • Move glslang to lib directory. #21139 (@sunag)
  • Refactor glslang import. #21149 (@Mugen87)

Editor

• Clean up. #21057 (@1993heqiang)
• Added pen support to EditorControls. #20951 (@arodic)
• Improve initial parameters of new orthogonal cameras. #20948 (@1993heqiang)
• Move to fflate. #20971, #20977, #20987 (@Mugen87)
• Fix remove function of UIPoints. #21011 (@Mugen87)
• Remove remaining dependencies to Geometry. #21085 (@Mugen87)
• Fix reference in Sidebar.Material.js. #21105 (@Mugen87)

Tests

• Add Object3D.DefaultMatrixAutoUpdate unit test. #20963 (@takahirox)
• Add Object3D.DefaultUp unit test. #20982 (@takahirox)

Utils

• Fix objectPath formatting to support Windows PC in packLDrawModel. #20964 (@lk-lkaz)