KeePassXC is a free and open-source password manager. It started as a community fork of KeePassX, which is itself fork of KeePass.
It is built using Qt5 libraries, making it a multi-platform application which can be run on Linux, Windows, and macOS.
KeePassXC uses the KeePass 2.x (.kdbx) password database format as the native format. It can also import (and convert) version 2 and the older KeePass 1 (.kdb) databases.
KeePassXC supports having key files and YubiKey challenge-response for additional security.