WordPerfect:
- WordPerfect is a word processing software developed by Corel Corporation.
- It has a long history and was once one of the most popular word processing programs.
- WordPerfect features advanced formatting and document creation capabilities.
- It supports a wide range of file formats, including its own proprietary format, Microsoft Word formats, and more.
- It is known for its robust features, especially for legal professionals and those who require advanced formatting control.

WordPad:
- WordPad is a basic word processing program included with Microsoft Windows operating systems.
- It is a simple text editor with basic formatting options like font styles and sizes, bold, italic, and underline.
- WordPad is intended for basic document editing and is not as feature-rich as more advanced word processors like Microsoft Word or WordPerfect.
- It is useful for quick note-taking and simple document creation.

Microsoft Word (MS Word):
- Microsoft Word is one of the most widely used word processing software in the world.
- It is part of the Microsoft Office suite of productivity software.
- Microsoft Word offers a wide range of features for creating, editing, and formatting documents, including advanced formatting, document templates, collaborative features, and more.
- It is widely used in professional, educational, and personal settings for creating a variety of documents, from letters and reports to resumes and academic papers.

So, all three of these options are word processing software.