DOC: Update README

Author: tbirdso

README.md

@@ -1,26 +1,36 @@
-ITK Python Package
-==================
+# ITK Python Package
 
 This project provides a `setup.py` script to build ITK Python binary
 packages and infrastructure to build ITK external module Python
 packages.
 
-ITK is an open-source, cross-platform system that provides developers
+The Insight Toolkit (ITK) is an open-source, cross-platform system that provides developers
 with an extensive suite of software tools for image analysis.
+More information is available on the [ITK website](https://itk.org/)
+or at the [ITK GitHub homepage](https://github.com/insightSoftwareConsortium/ITK).
 
-Installation
-------------
+## Using ITK Python Packages
 
-To install the ITK Python package:
+ITKPythonPackage scripts can be used to produce [Python](https://www.python.org/) packages
+for ITK and ITK external modules. The resulting packages can be
+hosted on the [Python Package Index (PyPI)](https://pypi.org/)
+for easy distribution.
+
+### Installation
+
+To install baseline ITK Python packages:
 
 ```sh
-     pip install itk
+> pip install itk
 ```
 
-Usage
------
+To install ITK external module packages:
 
-### Simple example script
+```sh
+> pip install itk-<module_name>
+```
+
+### Using ITK in Python scripts
 
 ```python
     import itk
@@ -36,15 +46,97 @@ Usage
     itk.imwrite(median, output_filename)
 ```
 
+### Other Resources for Using ITK in Python
+
 See also the [ITK Python Quick Start
 Guide](https://itkpythonpackage.readthedocs.io/en/master/Quick_start_guide.html).
-There are also many [downloadable examples documented in
-Sphinx](https://itk.org/ITKExamples/search.html?q=Python).
+There are also many [downloadable examples on the ITK examples website](https://examples.itk.org/search.html?q=Python).
 
 For more information on ITK's Python wrapping, [an introduction is
 provided in the ITK Software
 Guide](https://itk.org/ITKSoftwareGuide/html/Book1/ITKSoftwareGuide-Book1ch3.html#x32-420003.7).
 
+## Building with ITKPythonPackage
+
+ITK reusable workflows are available to build and package Python wheels as
+part of Continuous Integration (CI) via Github Actions runners.
+Those workflows can handle the overhead of fetching, configuring, and
+running ITKPythonPackage build scripts for most ITK external modules.
+See [ITKRemoteModuleBuildTestPackageAction](https://github.com/InsightSoftwareConsortium/ITKRemoteModuleBuildTestPackageAction)
+for more information.
+
+For special cases where ITK reusable workflows are not a good fit,
+ITKPythonPackage scripts can be directly used to build Python wheels
+to target Windows, Linux, and MacOS platforms. See
+[ITKPythonPackage ReadTheDocs](https://itkpythonpackage.readthedocs.io/en/master/Build_ITK_Module_Python_packages.html)
+documentation for more information on building wheels by hand.
+
+## Frequently Asked Questions
+
+### What target platforms and architectures are supported?
+
+ITKPythonPackage currently supports building wheels for the following platforms and architectures:
+- Windows 10 x86_64 platforms
+- Windows 11 x86_64 platforms
+- MacOS 10.9+ x86_64 platforms
+- MacOS 11.0+ arm64 platforms
+- Linux glibc 2.17+ (E.g. Ubuntu 18.04+) x86_64 platforms
+- _Coming Soon: Linux ARM platforms_
+
+### What should I do if my target platform/architecture does not appear on the list above?
+
+Please open an issue in the [ITKPythonPackage issue tracker](https://github.com/InsightSoftwareConsortium/ITKPythonPackage/issues)
+for discussion, and consider contributing either time or funding to support
+development. The ITK open source ecosystem is driven through contributions from its community members.
+
+### What is an ITK external module?
+
+The Insight Toolkit consists of several baseline module groups for image analysis
+including filtering, I/O, registration, segmentation, and more. Community members
+can extend ITK by developing an ITK "external" module which stands alone in a separate
+repository and its independently built and tested. An ITK external module which
+meets community standards for documentation and maintenance may be included in the
+ITK build process as an ITK "remote" module to make it easier to retrieve and build.
+
+Visit [ITKModuleTemplate](https://github.com/insightSoftwareConsortium/ITKmoduletemplate)
+to get started creating a new ITK external module.
+
+### How can I make my ITK C++ filters available in Python?
+
+ITK uses SWIG to wrap C++ filters for use in Python.
+See [Chapter 9 in the ITK Software Guide](https://itk.org/ITKSoftwareGuide/html/Book1/ITKSoftwareGuide-Book1ch9.html)
+or visit [ITKModuleTemplate](https://github.com/insightSoftwareConsortium/ITKmoduletemplate)
+to get started on writing `.wrap` files.
+
+After you've added wrappings for your external module C++ filters
+you may build and distribute Python packages automatically with
+[ITKRemoteModuleBuildTestPackageAction](https://github.com/InsightSoftwareConsortium/ITKRemoteModuleBuildTestPackageAction)
+or manually with ITKPythonPackage scripts.
+
+### What makes building ITK external module wheels different from building ITK wheels?
+
+In order to build an ITK external module you must have first built ITK for the same target platform.
+However, building ITK modules and wrapping them for Python can take a very long time!
+To avoid having to rebuilt ITK before building every individual external module,
+artifacts from the ITK build process (headers, source files, wrapper outputs, and more) are
+packaged and cached as [ITKPythonBuilds](https://github.com/insightSoftwareConsortium/ITKpythonbuilds)
+releases.
+
+In order to build Python wheels for an ITK external module, ITKPythonPackage scripts
+first fetch the appropriate ITK Python build artifacts along with other necessary
+tools. Then, the module can be built, packaged, and distributed on [PyPI](https://pypi.org/).
+
+### My external module has a complicated build process. Is it supported by ITKPythonPackage?
+
+Start by consulting the [ITKPythonPackage ReadTheDocs](https://itkpythonpackage.readthedocs.io/en/master/Build_ITK_Module_Python_packages.html)
+documentation and the [ITKPythonPackage issue tracker](https://github.com/InsightSoftwareConsortium/ITKPythonPackage/issues)
+for discussion related to your specific issue.
+
+If you aren't able to find an answer for your specific case, please start a discussion the
+[ITK Discourse forum](https://discourse.itk.org/) for help.
+
+## Additional Information
+
 -   Free software: Apache Software license
 -   Documentation: <http://itkpythonpackage.readthedocs.org>
 -   Source code: <https://github.com/InsightSoftwareConsortium/ITKPythonPackage>