KeePassX is an application for people with extremly high demands on secure personal data management. It has a light interface, is cross platform and published under the terms of the GNU General Public License.
Get KeePassX from: https://www.keepassx.org/
http://keepass.info/ - KeePass Password Safe
KeePass is a free open source password manager, which helps you to manage your passwords in a secure way. You can store all your passwords in one database, which is locked with a master key. So you only have to remember one single master key to unlock the whole database. Database files are encrypted using the best and most secure encryption algorithms currently known (AES-256, ChaCha20 and Twofish). For more information, see the features page.
https://keepassxc.org/ - KeePassXC - Cross-Platform Password Manager
Never forget a password again. Securely store passwords using industry standard encryption, quickly auto-type them into desktop applications, and use our browser extension to log into websites.
https://github.com/mstarke/MacPass - A native macOS KeePass client
MacPass is an attempt to create a native macOS port of KeePass on a solid open source foundation with a vibrant community pushing it further to become the best KeePass client for macOS.