The authors discuss the main premises of the project “The most popular surnames in Poland — past and present. E-dictionary” which has been in development since July 2014 in IJP PAN in Krakow. They also present its basic aims and functions, progress already made and they compare it with other dictionaries of surnames. The authors describe several aspects of the dictionary related to IT and computers but also those concerned with onomastics and lexicography. Additionally, they pay particular attention to the information contained in specific parts of each entry.