Exchange is MIT's enterprise-wide email and calendaring service.
IS&T provides a number of web services for accessing enterprise data or integrating with our central systems through the MIT Developer Connection. Application developers can integrate with or consume data from these systems using a standard protocol, instead of using a custom, application-specific protocol (Moira, MITID DB), or raw SQL (Data Warehouse, RolesDB).
MIT's LDAP Directory Service (ldap.mit.edu) is MIT's implementation of the standard LDAP protocol for providing directory services. It provides access to user and group membership information sourced from Moira and updated in real time, allowing application developers or administrators looking to integrate their applications with MIT's enterprise data.
Some examples within IS&T are wikis.mit.edu (based on Atlassian Confluence) and Stellar Forums (based on PHPBB), both of which make use of the LDAP service for user lookups.