What is LTI?
IMS Learning Tools Interoperability (LTI) is a standard set of specifications for allowing third party learning applications (or "tool providers") to integrate with educational platforms (or "tool consumers"). Translation: LTI lets you easily integrate external tools into your learning management system (LMS). Instead of each third party tool developing and maintaining a custom integration specific to a particular LMS, an LTI integration allows the application to connect to any LMS which supports the LTI standard.
You can think of it a little bit like a USB port. Before USB, you needed different types of cables to connect your mouse, keyboard, printer and other peripherals to your computer. Now, you can use the USB port to connect all sorts of things to your machine, whether it is a mouse, keyboard, printer, camera, headset, or some other device. As long as they all support USB, you can plug and play. The LTI standard is similar in that it makes it easy to integrate external applications using a single protocol. For the end user, the external application is presented seamlessly within the LMS, all without the need to maintain separate integrations for individual applications.
There are many third party tools which now support LTI, and more are being added everyday. Some examples of tool providers include things such as online publisher content, plagiarism detection services, eportfolio solutions, online tutoring services, and more. In most cases, the tool provider (or learning application) is hosted and maintained separately from the tool consumer (LMS). In many cases, there are separate licensing or hosting costs associated with these third party applications. Think of the concept of an "App Store." External LTI tool providers are like apps that you can choose to integrate with your LMS. Some apps are free, but many of them require a separate purchase or subscription.
Sakai fully supports LTI. (LTI 1.1 is supported in Sakai 2.9 and support for LTI 2.0 was introduced in Sakai 10.) This means that you can take advantage of the wide range of LTI tools available today within your Sakai system. If you'd like to view a list of LTI-enabled tools and platforms, check out the IMS LTI catalog: http://developers.imsglobal.org/catalog.html