The principal concept of LTI is to establish a standard way of integrating rich learning applications (often remotely hosted and provided through third-party services) with platforms like learning management systems, portals, or other educational environments. In LTI these learning applications are called Tools (delivered by Tool Providers) and the LMS, or platforms, are called Tool Consumers.
Here Discourse is LMS and comes under Tool Consumers. With this support Discourse will be able to hook with the various Tool Providers out there.
For example, BBB(Big Blue Button) http://bigbluebutton.org/ can be used in Discourse seamlessly.
For more information visit, Learning Tools Interoperability | IMS Global Learning Consortium