Three highly regarded options for DITA authoring include:

• Oxygen XML Editor: Oxygen XML Editor is widely recognized as one of the leading DITA authoring tools. It offers a robust set of features for DITA authoring, including content completion, validation, and integration with the DITA Open Toolkit for publishing. Oxygen XML Editor is known for its versatility and support for various XML-based standards.
• Adobe FrameMaker: Adobe FrameMaker is a powerful authoring and publishing tool that has extensive support for DITA. It provides a user-friendly interface for structured content creation and offers features for single-source publishing in multiple formats.
• MadCap Flare: MadCap Flare is known for its user-friendly interface and strong DITA support. It also features strong single-source publishing capabilities and content management features.