This package is designed for people who are a) interested in writing emulators or b) integrating this level of detain into their applications (e.g., a video game). The ability to do this is useful because a) it allows for tinkering far before physical implementation of the design is.
In addition to a strong core, WFCPK will also include modules emulating various processors (e.g., the MOS 6502 and the Zilog Z80) as well as the Video-Audio Interface (a custom VGA-compatible display and audio controller). The VAI is designed to fit within an FPGA to be integrated into real designs.
This library is licensed under the GPLv3 but also includes the classpath exception so that proprietary software can be linked against it required.