IBM home page for Virtual Telecommunications Access Method (VTAM); the z/OS version is part of Communications Server. Includes links to the latest version's announcement letter, documentation and storage estimates.
IBM home page for Data Interfile Transfer, Testing, and Operations Utility for ESA (DITTO/ESA). Overview of features with links to support, news, library and more information. DITTO runs on VSE/ESA, z/VM and z/OS.