KeePassXC
KeePassXC is a free and open-source password manager. It started as a community fork of KeePassX.
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 password database format as the native format. It can also import version 2 and the older KeePass 1 databases. KeePassXC supports having key files and YubiKey challenge-response for additional security.
The Electronic Frontier Foundation mention KeePassXC as "an example of a password manager that is open-source and free." The tech collective PrivacyTools has included KeePassXC in their list of recommended password manager software because of its active development.