The repository consists of multiple folders, initially of the following three folders: scijava, KNIME, C++ .
scijava: Here's the main Java implementation of the image transfer protocol, and Fiji plugins.
KNIME: Here's a KNIME source and sink nodes that call the scijava back-end to do the transfer.
C++: Here's a C++ mini-library that is compatible with the transfer protocol in scijava.
The protocol documentation, including a bit of rationale/motivation and example code, can be found as PDFs in the release/doc
folder.