Hypertext

Enhanced Definition

Hypertext, within the context of IBM z/OS, refers to text that contains embedded links to other text, documents, or media, enabling non-linear navigation. While not a native z/OS technology itself, mainframes play a crucial role in serving, generating, and interacting with hypertext, primarily through web-based interfaces and documentation.

Key Characteristics

- Non-linear Navigation: Allows users to jump between related pieces of information or different sections of a document via embedded links, rather than following a sequential path.
- Embedded Links: Contains clickable elements (hyperlinks) that point to other resources, which can be other documents, images, videos, or even applications.
- Web-Centric: Primarily associated with the World Wide Web, using HTML (Hypertext Markup Language) for structuring content and HTTP (Hypertext Transfer Protocol) for its transfer.
- Served by z/OS: IBM HTTP Server for z/OS (based on Apache) enables z/OS systems to host and deliver web pages containing hypertext content.
- User Interface Foundation: Forms the basis for modern web-based user interfaces that interact with traditional mainframe applications and data.

Use Cases

- Web-based Access to Mainframe Applications: Providing modern, browser-based front-ends for CICS, IMS, or DB2 applications, where users navigate through web pages (hypertext) to interact with backend transactions.
- Online Documentation and Help Systems: Delivering comprehensive, searchable, and interconnected documentation for z/OS products, utilities, and application systems in HTML format.
- Enterprise Portals: Integrating diverse mainframe data and applications into corporate intranets or extranets, often through web pages that link to various services and reports.
- z/OS Management Facility (z/OSMF): The primary web-based interface for managing z/OS, which extensively uses hypertext to link between different management tasks, dashboards, and configuration options.

Related Concepts

Hypertext is intrinsically linked to HTML (Hypertext Markup Language), the standard markup language for creating web pages, and HTTP (Hypertext Transfer Protocol), the application protocol for distributed, collaborative, hypermedia information systems. On z/OS, the IBM HTTP Server for z/OS is the key component that allows the mainframe to act as a web server, delivering hypertext content. It often works in conjunction with CICS Web Support, IMS Web Gateway, or custom z/OS UNIX System Services (USS) applications to expose mainframe transactions and data via web interfaces.

Best Practices:

Secure Web Services: Implement robust security measures for any web server on z/OS serving hypertext, including SSL/TLS encryption, strong authentication, authorization, and network segmentation.
Optimize Performance: Configure the IBM HTTP Server for z/OS for optimal performance, utilizing caching, compression, and efficient resource management to ensure fast delivery of hypertext content.
Accessibility Standards: Design web interfaces that interact with mainframe systems to comply with web accessibility guidelines (e.g., WCAG) to ensure usability for all users.
Maintainability and Modularity: Structure hypertext-based applications with clear separation of concerns, making them easier to maintain, update, and extend.
Leverage z/OS Capabilities: Utilize z/OS features like Workload Manager (WLM) to prioritize web server workloads and ensure high availability for hypertext-driven applications.