Free Java 8 Implementations

A paid license for java isn't required. Many companies use an open source, free java implementation. CollegeSource uses several free implementations instead of purchasing a commercial license. The next sections cover the essential aspects.

Java Version

Version 8 is required for the PeopleSoft T-Rex interface and the Transferology Connector, newer Java versions (9, 10, 11, ...) won't run the interface due to compatibility issues.

JRE Implementation

JRE are the initials for the Java Runtime Environment, it is the java program that must be installed at the institution. In simplest terms, the JRE provides the java program that actually runs the PeopleSoft T-Rex interface. Oracle previously provided the JRE for free, now they require a commercial license. As I stated above, since that change, CollegeSource hasn't purchased an Oracle license to use their JRE. We use two different open source, free JRE implementations, both are briefly discussed below.

OpenJDK

The OpenJDK project is provided by Oracle, it is the open source, free, reference implementation of Java. It is the starting point for a number of companies/organization's JRE implementations. In fact, it is the basis of Oracle's commercial product, which bundles other non essential functionality. Here's the OpenJDK page for java 8, the downloads are on the Binaries links:
https://wiki.openjdk.java.net/display/jdk8u

Amazon's Corretto

Non AWS customers are able to use Corretto, it is open source and free. Here's a description from their website:

"Amazon Corretto is a no-cost, multiplatform, production-ready distribution of the Open Java Development Kit (OpenJDK). Corretto comes with long-term support that will include performance enhancements and security fixes. Amazon runs Corretto internally on thousands of production services and Corretto is certified as compatible with the Java SE standard." 

Here's a link to their Java 8 downloads:
https://docs.aws.amazon.com/corretto/latest/corretto-8-ug/downloads-list.html

If you need more details, here's a lengthy paper from experts in the Java Community, titled Java Is Still Free:
https://docs.google.com/document/d/1nFGazvrCvHMZJgFstlbzoHjpAVwv5DEdnaBr_5pKuHo/edit#heading=h.p3qt2oh5eczi