DOC: Document development with Pixi

Pixi is not envisioned as the only way to develop ITK, but an easy and
reproducible way to set up a local development environment.

Provide an overview on how to install pixi, run ITK tests, and perform
more specific local development.

Documentation/docs/contributing/build_test_itk.md

@@ -0,0 +1,83 @@
+# Build and test ITK
+
+The [CMake] build system was initially created to support development of ITK; ITK is built following standard CMake practices.
+
+ITK's tests are defined with CTest, and the tests can be executed via `ctest`.
+
+## Pixi
+
+An easy and reproducible way to build and test ITK for development is via [Pixi]. Pixi will provide locally-scoped build tools such as toolchains, `cmake`, `ninja`,  and `python`.
+
+First, install `pixi`,
+
+::::{tab-set}
+
+:::{tab-item} Linux & macOS
+```shell
+curl -fsSL https://pixi.sh/install.sh | bash
+```
+:::
+
+:::{tab-item} Windows
+`PowerShell`:
+```powershell
+iwr -useb https://pixi.sh/install.ps1 | iex
+```
+`winget`:
+```
+winget install prefix-dev.pixi
+```
+:::
+
+::::
+
+or use [another pixi installation option].
+
+You might need to restart your terminal or source your shell for the changes to take effect.
+
+ITK's Pixi configuration uses the [conda-forge compiler] and the [Ninja] CMake generator.
+
+### Test C++
+
+To configure, build, and run ITK's C++ tests,
+
+```shell
+# Change to the ITK source directory
+cd src/ITK
+
+pixi run test
+```
+
+### Test Python
+
+To configure, build, and run ITK's Python bindings and run the Python and C++ tests,
+
+```shell
+# Change to the ITK source directory
+cd src/ITK
+
+pixi run test-python
+```
+
+### Further testing and development
+
+Additional pixi tasks to run specific steps of the `configure`, `build`, `test` development process or create builds with other [CMake build types] are listed with
+
+```shell
+pixi task list
+```
+
+To start up a shell environment with all build dependencies:
+
+```shell
+pixi shell
+```
+
+Once in the pixi shell, `cmake`, `ninja`, `ctest`, etc can be executed in the local `build/` directory containing the build to perform targeted development.
+
+[another pixi installation option]: https://pixi.sh/latest/#installer-script-options
+[CMake]: https://cmake.org/
+[CMake build types]: https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html
+[conda-forge compiler]: https://anaconda.org/conda-forge/cxx-compiler
+[Ninja]: https://ninja-build.org/
+[Pixi]: https://pixi.sh/

Documentation/docs/contributing/index.md

@@ -41,9 +41,16 @@ the [`setup-git-aliases`] script for general Git tasks in ITK.
 Visit the *Pro Git: Setup* resource in [Git Help] for further
 information on setting up your local Git environment.
 
+(build)=
+Local Build and Testing
+-----------------------
+
+See our guide on how to [build and test ITK] to make and test your change
+locally.
+
 (workflow)=
-Workflow
---------
+Git Workflow
+------------
 
 ITK development uses a branchy workflow based on topic branches.
 This corresponds to the *Fork & Pull Model* mentioned in the
@@ -387,6 +394,7 @@ Actual releases have tags named by the release version number.
 :maxdepth: 3
 :caption: 📖 More Information
 
+build_test_itk.md
 ITK Software Guide, Book 1, Part III: Development Guidelines <https://itk.org/ItkSoftwareGuide.pdf>
 git_help.md
 GitHub flow guide <https://guides.github.com/introduction/flow/index.html>
@@ -405,6 +413,7 @@ python_packaging.md
 [ITK Git Cheatsheet]: ./GitCheatSheet.pdf
 [download instructions]: ../download.md
 [Updating Third Party]: ./updating_third_party.md
+[build and test ITK]: ./build_test_itk.md
 
 [`SetupForDevelopment.sh`]: https://github.com/InsightSoftwareConsortium/ITK/blob/master/Utilities/SetupForDevelopment.sh
 [`setup-git-aliases`]: https://github.com/InsightSoftwareConsortium/ITK/blob/master/Utilities/GitSetup/setup-git-aliases

pyproject.toml

@@ -119,7 +119,7 @@ outputs = ["build-debug/CMakeFiles/"]
 
 [tool.pixi.feature.python.tasks.build-debug-python]
 cmd = "cmake --build build-debug-python"
-description = "Build ITK - Debug"
+description = "Build ITK Python - Debug"
 outputs = ["build-debug/lib/**"]
 depends-on = ["configure-debug-python"]