Any implementation of a Java Card runtime environment (Java Card RE) contains a virtual machine (VM) for the Java Card platform, the Java Card Application Programming Interface (API) classes, and support services.
The Classic Edition architecture illustrated is built on the classic Java Card VM, which is similar to the VM from previous releases of the Java Card development kit starting with version 2.2.2. Likewise, the classic APIs are similar to the APIs from previous releases.
Figure 1-1 Classic Edition Architecture
This development kit includes a Java Card RE that simulates a Java Card 3 Platform, Classic Edition as it would be implemented onto a smart card. This Java Card RE is the reference implementation (RI), and is invoked on the command line with
cref.bat. The RI implements the ISO 7816-4:2013 specification, including support for up to twenty logical channels and the extended APDU extensions as defined in ISO 7816-3. For more information on the RI, see Using the Reference Implementation.