Some aspects of Foundry may be open source. Commercial modules wouldnt be. I havent played with others
nostr:nprofile1qqsrgejevq62esh90agvxvhxkz2lftkfghl8aw0rce79tm97dwn5v2qpzamhxue69uhkuetjdaehgu3w0pkhytnjda3kkucprpmhxue69uhhyetvv9ujuumwdae8gtnnda3kjctvqy8hwumn8ghj7mn0wd68ytnddaksa0qcjh is the guy thats been setting up and running Foundry and could give more ppinters