Apologies for any redundancy in my previous responses. Building upon the information provided earlier, here’s an updated and detailed list of the Top 21 Content Management Systems (CMS) and Their Major Features:

1. WordPress

WordPress is the most widely used CMS, powering over 40% of websites globally. It offers extensive customization through thousands of themes and plugins.

Major Features:

• Open-source and free: Accessible to everyone without licensing fees.
• Extensive plugin ecosystem: Enhance functionality with a vast array of plugins.
• SEO-friendly: Built-in features and plugins to optimize search engine rankings.
• User-friendly dashboard: Intuitive interface suitable for beginners and experts alike.

2. Joomla

Joomla is a flexible CMS suitable for building a variety of websites, from simple blogs to complex corporate sites.

Major Features:

• Multilingual support: Built-in translation capabilities for diverse audiences.
• User management: Advanced system for managing user permissions and groups.
• Extensive extensions library: Thousands of extensions to add functionalities.
• SEO optimization: Tools to enhance search engine visibility.

3. Drupal

Drupal is known for its robustness and scalability, making it ideal for complex and large-scale websites.

Major Features:

• Highly customizable: Flexible content architecture for bespoke solutions.
• Strong security: Regular updates and a dedicated security team.
• Multisite capability: Manage multiple sites from a single installation.
• Extensive API support: Facilitates integration with other applications.

4. Magento (Adobe Commerce)

Magento, now known as Adobe Commerce, is a leading CMS for e-commerce platforms, offering a range of features tailored for online stores.

Major Features:

• Product management: Advanced tools for cataloging and managing products.
• Flexible shopping cart system: Supports multiple payment and shipping options.
• Scalable architecture: Handles large inventories and high traffic volumes.
• SEO and marketing tools: Built-in features to promote products and optimize search rankings.

5. Shopify

Shopify is a user-friendly e-commerce CMS that enables businesses to set up online stores quickly.

Major Features:

• Hosted solution: No need to worry about server management.
• App integrations: Access to a wide range of apps to extend store functionality.
• Responsive themes: Professional designs that work on all devices.
• Secure payment gateways: Supports various payment options with robust security.

6. Wix

Wix offers a cloud-based platform with a drag-and-drop interface, making website creation accessible to non-developers.

Major Features:

• Intuitive design editor: Easily customize site appearance without coding.
• App Market: Add functionalities like forms, chats, and booking systems.
• SEO tools: Optimize your site for search engines with built-in features.
• Mobile optimization: Ensure your site looks great on all devices.

7. Squarespace

Squarespace is known for its design-centric approach, offering visually appealing templates suitable for creatives and businesses.

Major Features:

• Award-winning templates: Professionally designed themes for a polished look.
• Integrated e-commerce: Sell products and services directly from your site.
• Built-in blogging platform: Share updates and engage with your audience.
• Analytics: Monitor site performance with in-depth analytics tools.

8. Webflow

Webflow combines a CMS with a visual web design tool, allowing designers to build responsive websites without coding.

Major Features:

• Visual design interface: Design and develop simultaneously with a visual canvas.
• CMS for dynamic content: Create and manage complex content structures.
• Hosting included: Fast and reliable hosting services.
• SEO controls: Optimize your site with customizable SEO settings.

9. TYPO3

TYPO3 is an enterprise-level CMS offering extensive features for large-scale websites and intranets.

Major Features:

• Scalability: Handles large amounts of content and high traffic.
• Granular permissions: Detailed user access control for complex workflows.
• Multilingual support: Manage content in multiple languages seamlessly.
• Extensible with extensions: Enhance functionality with a wide range of extensions.

10. HubSpot CMS Hub

HubSpot CMS Hub integrates content management with CRM and marketing tools, providing a unified platform for businesses.

Major Features:

• Personalization: Deliver tailored content to visitors based on their behavior.
• SEO recommendations: Built-in tools to optimize content for search engines.
• Drag-and-drop editor: Easily create and edit pages without coding.
• Integrated analytics: Monitor performance and gain insights from a single dashboard.

11. Ghost

Ghost is a minimalist CMS focused on professional publishing, offering a streamlined experience for bloggers and writers.

Major Features:

• Markdown editor: Write content using simple markdown syntax.
• SEO and social sharing:

12. Optimizely Content Management System

Optimizely offers a robust CMS designed to deliver personalized digital experiences. It combines content management with powerful experimentation and optimization tools.

Major Features:

• Personalization: Delivers tailored content to users based on behavior and preferences.
• A/B Testing: Built-in tools to experiment with different content variations.
• Scalability: Supports enterprise-level content needs with high performance.
• Integration Capabilities: Seamlessly connects with various marketing and analytics tools.

13. Contentful

Contentful is a headless CMS that provides a flexible content infrastructure, allowing developers to deliver content across various platforms and devices.

Major Features:

• API-First Approach: Delivers content via RESTful and GraphQL APIs.
• Content Modeling: Define custom content types and structures.
• Multi-Channel Delivery: Publish content across websites, mobile apps, and IoT devices.
• Extensibility: Integrates with various third-party services and tools.

14. Sanity

Sanity is a headless CMS known for its real-time collaboration and flexible content modeling capabilities.

Major Features:

• Real-Time Collaboration: Multiple users can edit content simultaneously.
• Customizable Content Studio: Tailor the editing interface to fit specific workflows.
• Structured Content: Supports complex content relationships and structures.
• Scalability: Handles large datasets and high traffic efficiently.

15. Prismic

Prismic is a headless CMS that emphasizes a component-based approach to content management, enabling developers and marketers to collaborate effectively.

Major Features:

• Slice Machine: Create reusable content components for dynamic page building.
• Multi-Language Support: Manage content in multiple languages seamlessly.
• Content Scheduling: Plan and schedule content releases in advance.
• API-Driven: Delivers content through a robust API for flexibility.

16. Hygraph

Hygraph is a GraphQL-native headless CMS that offers a highly customizable content management experience for developers.

Major Features:

• GraphQL API: Provides a powerful and flexible query language for content delivery.
• Content Federation: Unify content from multiple sources into a single API.
• Localization: Manage and deliver content in various languages.
• Extensibility: Supports custom plugins and integrations to enhance functionality.

17. Adobe Experience Manager (AEM)

Adobe Experience Manager is an enterprise-grade CMS that combines digital asset management with robust content management capabilities.

Major Features:

• Digital Asset Management: Centralized repository for managing media assets.
• Personalization: Delivers customized content experiences to users.
• Integration with Adobe Suite: Seamlessly works with other Adobe products for a unified workflow.
• Scalability: Supports large-scale content operations for global enterprises.

18. Sitecore

Sitecore is a digital experience platform that offers comprehensive content management and marketing automation tools.

Major Features:

• Personalization: Real-time user data to deliver personalized content.
• Analytics: In-depth insights into user behavior and content performance.
• Multi-Channel Delivery: Consistent content experience across various platforms.
• Integration Capabilities: Connects with numerous third-party applications and services.

19. Contentstack

Contentstack is a headless CMS that focuses on empowering businesses to deliver omnichannel digital experiences with speed and efficiency.

Major Features:

• API-First Architecture: Facilitates seamless integration with various platforms.
• Collaboration Tools: Enhances teamwork with features like workflows and role-based access.
• Scalability: Handles high traffic and large volumes of content effortlessly.
• Extensibility: Offers a marketplace for integrations and extensions to enhance functionality.

20. DatoCMS

DatoCMS is a headless CMS that provides a user-friendly interface for content creators and a robust API for developers.

Major Features:

• GraphQL API: Enables efficient and flexible content querying.
• Media Management: Advanced tools for handling images and videos.
• Localization: Supports multi-language content management.
• Plugin System: Extend functionality with a wide range of plugins.

21. Strapi

Strapi is an open-source headless CMS that offers complete customization and control over content management and API generation.

Major Features:

• Customization: Fully customizable admin panel and API.
• Authentication & Permissions: Built-in user roles and permissions management.
• Plugin Ecosystem: Extend capabilities with a variety of plugins.
• Self-Hosted: Complete control over data and hosting environment.

These CMS platforms offer a range of features tailored to different business needs, from simple website management to complex, enterprise-level content operations.