synagogue of the Libertines - Jewish freedmen; manumitted Roman captives, or the children of such, expelled from Rome (as appears from Josephus and Tacitus), and now residing at Jerusalem.
Cyrenians - Jews of Cyrene, in Libya, on the coast of Africa.
them of Cilicia - amongst whom may have been Saul of Tarsus (Act 7:58; Act 21:39).