Before the HTML is stored in the database, White Space Filter removes all duplications of white space's. This will results in smaller text fields, less disk space, and smaller files.
Parallel to the Services module, the Clients module provides the ability to implement pluggable clients to external web services, including external Drupal sites running the Services module, the main use case being connecting to other Drupal installs via the Services module with either the REST or XMLRPC server.
Clients module allows you to create connections to remote services with an admin UI. These handle fetching a result from a remote service. Different types of connection are provided for different types of services. There is a Drupal client connection type for different versions of Services (5.x-0.92, 6.x-2.x, 7.x-3.x), hence Clients can be used to connect to sites with different versions of Drupal.
Resources can be defined on top of connections, which provide an abstraction layer so that other parts of Drupal can work with remote data without needing to know anything about the connection. An example module for remote Views blocks is included.
Connections and resources can be exported to Features. The UI also provides a system for testing connections are correctly set up and functioning, which can be extended to provide site-specific tests.