A published description of PROPheT can be found in:

Panagiotis Mitzias, Marina Riga, Efstratios Kontopoulos, Thanos G. Stavropoulos, Stelios Andreadis, Georgios Meditskos, Ioannis Kompatsiaris. (2016). User-Driven Ontology Population from Linked Data Sources. In Knowledge Engineering and Semantic Web: 7th International Conference, KESW 2016, Prague, Czech Republic, September 21-23, 2016, pp. 31-41. DOI=10.1007/978-3-319-45880-9_3 (File also downloadable from: Download)

For those wishing to contribute to the development of PROPheT, the source code can be found at https://github.com/MKLab-ITI/prophet.