Is Geosparc Geomajas a fork of Geomajas?

No, and Geosparc continuously works to ensure that such a thing never occurs. All Geosparc created patches are submitted back to the Geomajas project in a timely fashion. Geosparc developers work closely with core maintainers and contributed module maintainers to ensure that there is little or no divergence between Geosparc Geomajas source code and the source code of available on Geomajas.org.