[Diff since v10.27.0](v10.27.0...v10.28.0)

**Merged pull requests:**
- feat: add `SemilinearODEFunction` and `SemilinearODEProblem` (#3739) (@AayushSabharwal)
- feat: add `discrete_inputs` (#4010) (@AayushSabharwal)
- Update Project.toml (#4021) (@AayushSabharwal)

**Closed issues:**
- Why does `remake` ignore my `u0`? (#3661)

[Diff since v10.26.1](v10.26.1...v10.27.0)

**Merged pull requests:**
- fix: fix minor bug in `generate_initializesystem` (#3931) (@AayushSabharwal)
- gui_metadata fix (#3984) (@bradcarman)
- Fix noise kwarg propagation for SDEProblem(f::SDESystem) (#3985) (@ChrisRackauckas-Claude)
- Update README (#3987) (@TorkelE)
- Prevents erroneous creation of discrete events (vector of conditions) (#3992) (@TorkelE)
- Fix spell check error (#3993) (@TorkelE)
- fix: fix incorrect incidence after tearing some differential equations (#3994) (@AayushSabharwal)
- add test for passing params as structural params (#3995) (@hexaeder)
- fix: fix generated `getindex` and `length` for `MTKParameters` (#3997) (@AayushSabharwal)
- Fix deprecated ODEProblem API calls in documentation (#4000) (@ChrisRackauckas-Claude)
- feat: support zero-arg operators (#4001) (@AayushSabharwal)
- fix: fix array discrete parameters (#4002) (@AayushSabharwal)
- test: make optimization sparse hessian test independent of variable order (#4003) (@AayushSabharwal)
- refactor: modularize tearing (#4004) (@AayushSabharwal)
- Backport #3733 (update to DI@0.7) to MTK@9 (#4011) (@devmotion)
- Fix IONotFoundError for disturbance inputs (#4014) (@baggepinnen)
- build: bump minor version (#4016) (@AayushSabharwal)

**Closed issues:**
- MTK allows you to create faulty events without throwing an error. (#2612)
- noise kwarg for SDEProblem(f::SDESystem) (#3664)
- Support for Inputs (#3823)
- using `subset_tunables` leads to bounds error with ForwardDiff for a DAE (#3925)
- Different solutions for seeded SDEProblems from ModelingToolkit and StochasticDiffEq (#3971)
- Terminate simulation on event (#3981)
- `get_component_type` errors on compiled systems (#3983)
- Cannot update vector parameters with (#3990)
- Deprecated calling of ODEProblem in the getting-started "Copy-Pastable Simplified Example" (#3996)

[Diff since v9.83.0](v9.83.0...v9.84.0)

This release has been identified as a backport.
Automated changelogs for backports tend to be wildly incorrect.
Therefore, the list of issues and pull requests is hidden.
<!--
**Merged pull requests:**
- fix: fix minor bug in `generate_initializesystem` (#3931) (@AayushSabharwal)
- fix: fix `ODEProblem` construction during precompilation with `eval_expression = true` (#3957) (@AayushSabharwal)
- Add DataStructures v0.17-v0.19 compatibility with version branching (#3959) (@ChrisRackauckas-Claude)
- fix: unwrap inputs/outputs in `System` constructor (#3960) (@vyudu)
- fix: retain inputs when compose (#3961) (@vyudu)
- Simply fractional_to_ordinary.jl tests with using OrdinaryDiffEq radau5 (#3963) (@ChrisRackauckas)
- CompatHelper: bump compat for Optimization to 5 for package docs, (keep existing compat) (#3966) (@github-actions[bot])
- build: bump minor version (#3967) (@AayushSabharwal)
- Handle `split` in `linearize_symbolic` (#3968) (@baggepinnen)
- refactor: remove dead code calling explicitfun in `SCCNonlinearProblem` (#3980) (@AayushSabharwal)
- build: bump patch version (#3982) (@AayushSabharwal)
- gui_metadata fix (#3984) (@bradcarman)
- Fix noise kwarg propagation for SDEProblem(f::SDESystem) (#3985) (@ChrisRackauckas-Claude)
- Update README (#3987) (@TorkelE)
- Prevents erroneous creation of discrete events (vector of conditions) (#3992) (@TorkelE)
- Fix spell check error (#3993) (@TorkelE)
- fix: fix incorrect incidence after tearing some differential equations (#3994) (@AayushSabharwal)
- add test for passing params as structural params (#3995) (@hexaeder)
- fix: fix generated `getindex` and `length` for `MTKParameters` (#3997) (@AayushSabharwal)
- Fix deprecated ODEProblem API calls in documentation (#4000) (@ChrisRackauckas-Claude)
- feat: support zero-arg operators (#4001) (@AayushSabharwal)
- fix: fix array discrete parameters (#4002) (@AayushSabharwal)
- test: make optimization sparse hessian test independent of variable order (#4003) (@AayushSabharwal)
- refactor: modularize tearing (#4004) (@AayushSabharwal)
- Backport #3733 (update to DI@0.7) to MTK@9 (#4011) (@devmotion)

**Closed issues:**
- MTK allows you to create faulty events without throwing an error. (#2612)
- noise kwarg for SDEProblem(f::SDESystem) (#3664)
- Support for Inputs (#3823)
- using `subset_tunables` leads to bounds error with ForwardDiff for a DAE (#3925)
- inputs lost when composing systems? (#3943)
- ModelingToolkit can't find a variable its knows as an unkown (#3964)
- Different solutions for seeded SDEProblems from ModelingToolkit and StochasticDiffEq (#3971)
- Terminate simulation on event (#3981)
- `get_component_type` errors on compiled systems (#3983)
- Cannot update vector parameters with (#3990)
- Deprecated calling of ODEProblem in the getting-started "Copy-Pastable Simplified Example" (#3996)

-->

[Diff since v10.26.0](v10.26.0...v10.26.1)

**Merged pull requests:**
- CompatHelper: bump compat for Optimization to 5 for package docs, (keep existing compat) (#3966) (@github-actions[bot])
- Handle `split` in `linearize_symbolic` (#3968) (@baggepinnen)
- refactor: remove dead code calling explicitfun in `SCCNonlinearProblem` (#3980) (@AayushSabharwal)
- build: bump patch version (#3982) (@AayushSabharwal)

**Closed issues:**
- ModelingToolkit can't find a variable its knows as an unkown (#3964)

[Diff since v10.25.0](v10.25.0...v10.26.0)

**Merged pull requests:**
- fix: fix `ODEProblem` construction during precompilation with `eval_expression = true` (#3957) (@AayushSabharwal)
- fix: unwrap inputs/outputs in `System` constructor (#3960) (@vyudu)
- fix: retain inputs when compose (#3961) (@vyudu)
- Simply fractional_to_ordinary.jl tests with using OrdinaryDiffEq radau5 (#3963) (@ChrisRackauckas)
- build: bump minor version (#3967) (@AayushSabharwal)

**Closed issues:**
- inputs lost when composing systems? (#3943)

[Diff since v10.24.0](v10.24.0...v10.25.0)

**Merged pull requests:**
- Update FAQ.md: add link to Basic Example on Optimization (#3955) (@bgctw)
- Backport #3843 (support of ForwardDiff@1) to MTK@9 (#3958) (@devmotion)
- Add DataStructures v0.17-v0.19 compatibility with version branching (#3959) (@ChrisRackauckas-Claude)

**Closed issues:**
- Cannot install latest ModelingToolkit release (#3951)

[Diff since v9.82.0](v9.82.0...v9.83.0)

This release has been identified as a backport.
Automated changelogs for backports tend to be wildly incorrect.
Therefore, the list of issues and pull requests is hidden.
<!--
**Merged pull requests:**
- Add support for an external synchronous compiler to discrete and hybrid systems (#3399) (@BenChung)
- feat: use `LinearProblem` for linear SCCs in `SCCNonlinearProblem` (#3760) (@AayushSabharwal)
- Transformation function to turn FDEs into ODEs (#3776) (@fchen121)
- feat: more robust inputs/outputs handling (#3795) (@AayushSabharwal)
- fix: fix `get_mtkparameters_reconstructor` handling of nonnumerics (#3796) (@AayushSabharwal)
- Disable unit checking of initialization problem during remake (#3797) (@contradict)
- refactor: format (#3803) (@AayushSabharwal)
- fix: fix bad input ordering, make downstream tests pass (#3804) (@AayushSabharwal)
- feat: make deprecated `ODESystem` alias `System` type (#3806) (@AayushSabharwal)
- build: bump minor version (#3807) (@AayushSabharwal)
- feat: rewrite clock inference to support polyadic synchronous operators (#3808) (@AayushSabharwal)
- Fix downstream linearization test (#3809) (@contradict)
- Fix typo (#3810) (@asinghvi17)
- fix: compile symbolic affects after `mtkcompile` in `complete` (#3812) (@AayushSabharwal)
- test: disable CasADi tests on Julia-v1.10 (#3817) (@AayushSabharwal)
- refactor: move `@compile_workload` to after exports (#3818) (@AayushSabharwal)
- test: `LinearProblem` tests are no longer broken (#3821) (@AayushSabharwal)
- fix: fix parameter dependencies dependent on scalarized array parameter (#3822) (@AayushSabharwal)
- feat: generate `SciMLBase.ODE_NLProbData` (#3827) (@AayushSabharwal)
- build: bump minor version (#3830) (@AayushSabharwal)
-  feat: make `nlprobmap` in-place  (#3832) (@AayushSabharwal)
- fix `reorder_unknowns` (#3833) (@baggepinnen)
- ci(tests): use the latest "pre-release" version of the reusable workflow (#3836) (@thazhemadam)
- fix: fix @mtkbuild not working when @mtkcompile is not imported (#3841) (@AayushSabharwal)
- update ForwardDiff to 1 (#3843) (@oscardssmith)
- fix: fix `OptimizationFunction` generation of exprs (#3844) (@AayushSabharwal)
- Apply JuliaFormatter v2 to fix formatting CI (#3845) (@ChrisRackauckas)
- Apply JuliaFormatter to fix code formatting (#3846) (@ChrisRackauckas)
- Remove outdated Julia version checks from tests (#3847) (@ChrisRackauckas)
- Remove nonlinearsolve as a dep by just using the default nonlinearsolve (#3851) (@ChrisRackauckas)
- Document EvalAt operator (#3852) (@ChrisRackauckas)
- Add downgrade CI workflow with InterfaceI test group (#3854) (@ChrisRackauckas)
- Fix deprecated ODESystem and @mtkbuild usage in documentation examples (#3856) (@ChrisRackauckas)
- Fix CI deprecation warnings (#3858) (@ChrisRackauckas)
- [ci-skip] Revert JuliaFormatter PR #3846 (#3860) (@ChrisRackauckas)
- Add solver kwargs to prob docstrings (#3861) (@ChrisRackauckas)
- Apply JuliaFormatter to fix code formatting (#3862) (@ChrisRackauckas)
- fix: fix incorrect metadata handling in symbolic affect simplification (#3868) (@AayushSabharwal)
- Add nlstep_compile as a debug tool for turning off simplification (#3873) (@ChrisRackauckas)
- fix: fix single-element symbolic tstops (#3874) (@AayushSabharwal)
- Forward `split` to `mtkcompile` (#3875) (@DhairyaLGandhi)
- fix: unwrap substitution rules in `nlstep=true` (#3877) (@AayushSabharwal)
- build: bump minor version (#3878) (@AayushSabharwal)
- Fix cache issues with self-hosted runners (#3879) (@ChrisRackauckas-Claude)
- CompatHelper: bump compat for ImplicitDiscreteSolve to 1, (keep existing compat) (#3880) (@github-actions[bot])
- fix deprecated ODEProblem syntax in Debugging.md (#3881) (@asinghvi17)
- refactor: mark several functions as public API (#3884) (@AayushSabharwal)
- Fix orientation getter (#3885) (@baggepinnen)
- chore: add `change_tunables` (#3886) (@DhairyaLGandhi)
- Add missing API documentation for all exported symbols (#3887) (@ChrisRackauckas-Claude)
- test: avoid intermittent stack overflow in test (#3889) (@AayushSabharwal)
- fix: fix simplification of empty systems (#3890) (@AayushSabharwal)
- feat: add `SCCNonlinearProblem` target for nlstep (#3891) (@AayushSabharwal)
- Allow system level metadata information (#3892) (@DhairyaLGandhi)
- Updated tests for the new behaviour of SymbolicUtils simplify function (#3893) (@Bumblebee00)
- fix: fix callback with non-`Real` parameter and non-empty unknowns (#3894) (@AayushSabharwal)
- feat: ensure causal connectors generate causally ordered equations (#3898) (@AayushSabharwal)
- build: bump minor version (#3899) (@AayushSabharwal)
- feat: add `respecialize` (#3900) (@AayushSabharwal)
- fix: use improved discrete saving API (#3901) (@AayushSabharwal)
- build: bump minor version (#3904) (@AayushSabharwal)
- build: bump minor version (#3918) (@AayushSabharwal)
- Improve Printing of Uninitialized Variables (#3920) (@DhairyaLGandhi)
- Copy parameter object before setting in `subset_tunables` (#3922) (@DhairyaLGandhi)
- Remove draft mode from documentation (#3933) (@hersle)
- CompatHelper: add new compat entry for OptimizationOptimJL at version 0.4 for package docs, (keep existing compat) (#3936) (@github-actions[bot])
- CompatHelper: add new compat entry for Optimization at version 4 for package docs, (keep existing compat) (#3937) (@github-actions[bot])
- Use matrix-dependent solver for sparse analytical Jacobian example (#3938) (@hersle)
- fix: fix sparse cost hessian (#3940) (@AayushSabharwal)
- build: bump minor version (#3941) (@AayushSabharwal)
- CompatHelper: bump compat for SymbolicUtils to 4, (keep existing compat) (#3945) (@github-actions[bot])
- CompatHelper: bump compat for SymbolicUtils to 4 for package docs, (keep existing compat) (#3946) (@github-actions[bot])
- Revert "CompatHelper: bump compat for SymbolicUtils to 4, (keep existing compat)" (#3947) (@ChrisRackauckas)
- Fix Jacobian sparsity pattern with observed derivatives (#3949) (@hersle)
- Make debugging page shorter (#3950) (@hersle)
- Update FAQ.md: add link to Basic Example on Optimization (#3955) (@bgctw)
- Backport #3843 (support of ForwardDiff@1) to MTK@9 (#3958) (@devmotion)

**Closed issues:**
- Unintuitive behavior for including metadata in @parameters/@variables begin end (#2770)
- Observed variables are computed even when unused (#2902)
- SDESystem example MTKv10.0.1 error (#3687)
- Allow subsetting tunables after system creation (#3772)
- `@compile_workload` should run after any `export` statements (#3811)
- ModelingToolkit.reorder_unknowns() returns the wrong permutation? (#3814)
- Add `new()` syntax to events (#3825)
- Support for Synchronous Systems (#3826)
- ERROR: LoadError: Internal Error. Please open an issue with an MWE. (#3835)
- Document `EvalAt` (#3849)
- `split` not forwarded from `generate_control_function` (#3859)
- Sparse ODE segfaults when RHS contains differentiated variable (#3871)
- Control function doesn't work: BoundsError: attempt to access Tuple{Vector{Any}, Nothing} at index [3] (#3872)
- nlstep broken for modelingtoolkitize (#3876)
- `respecialize` always promotes `Float16` and `Float32` to `Float64` (#3908)
- Precompile Issue [?SomePackage] (#3909)
- FMU variable names cannot be typed (#3913)
- ForwardDiff on ODE with callback crashes (#3914)
- `subset_tunables` seems to modify the system in-place (#3921)
- Permit `ComponentArray`s as simulation condition (u0 + ps) (#3926)
- Documentation is built in draft mode and does not show example block output (#3932)
- Cannot install latest ModelingToolkit release (#3951)

-->

[Diff since v10.23.0](v10.23.0...v10.24.0)

**Merged pull requests:**
- Improve Printing of Uninitialized Variables (#3920) (@DhairyaLGandhi)
- Copy parameter object before setting in `subset_tunables` (#3922) (@DhairyaLGandhi)
- CompatHelper: bump compat for SymbolicUtils to 4, (keep existing compat) (#3945) (@github-actions[bot])
- CompatHelper: bump compat for SymbolicUtils to 4 for package docs, (keep existing compat) (#3946) (@github-actions[bot])
- Revert "CompatHelper: bump compat for SymbolicUtils to 4, (keep existing compat)" (#3947) (@ChrisRackauckas)
- Fix Jacobian sparsity pattern with observed derivatives (#3949) (@hersle)

**Closed issues:**
- Sparse ODE segfaults when RHS contains differentiated variable (#3871)
- FMU variable names cannot be typed (#3913)
- `subset_tunables` seems to modify the system in-place (#3921)

[Diff since v10.22.0](v10.22.0...v10.23.0)

**Merged pull requests:**
- Transformation function to turn FDEs into ODEs (#3776) (@fchen121)
- Allow system level metadata information (#3892) (@DhairyaLGandhi)
- Remove draft mode from documentation (#3933) (@hersle)
- CompatHelper: add new compat entry for OptimizationOptimJL at version 0.4 for package docs, (keep existing compat) (#3936) (@github-actions[bot])
- CompatHelper: add new compat entry for Optimization at version 4 for package docs, (keep existing compat) (#3937) (@github-actions[bot])
- Use matrix-dependent solver for sparse analytical Jacobian example (#3938) (@hersle)
- fix: fix sparse cost hessian (#3940) (@AayushSabharwal)
- build: bump minor version (#3941) (@AayushSabharwal)

**Closed issues:**
- Permit `ComponentArray`s as simulation condition (u0 + ps) (#3926)
- Documentation is built in draft mode and does not show example block output (#3932)

[Diff since v10.21.0](v10.21.0...v10.22.0)

**Merged pull requests:**
- fix: use improved discrete saving API (#3901) (@AayushSabharwal)
- build: bump minor version (#3918) (@AayushSabharwal)

**Closed issues:**
- ERROR: LoadError: Internal Error. Please open an issue with an MWE. (#3835)
- `respecialize` always promotes `Float16` and `Float32` to `Float64` (#3908)
- Precompile Issue [?SomePackage] (#3909)
- ForwardDiff on ODE with callback crashes (#3914)