KeePassXC 2.5.0 was released recently with important improvements, like an option to export a database to an HTML file (for paper backup), database statistics, re-enabled Wayland support, and more.
KeePassXC is a free and open-source password manager started as a community fork of KeePassX (which itself is a fork of KeePass), which is not actively maintained. The application is built using Qt and runs on Linux, Windows and macOS. For its database, KeePassXC uses the KeePass 2.x (.kdbx) password database format as its native file format in versions 3.1 and 4, using AES encryption with a 256 bit key.
There's no cloud synchronization built into KeePassXC, but this can easily be done through third-party cloud provides like Dropbox, Google Drive, Nextcloud, and so on.
As for web browser integration, KeePassXC supports this with the help of an extension available for Firefox or Chrome-based (Google Chrome, Chromium, Vivaldi, etc.) web browsers.
Compared to KeePassX, KeePassXC includes numerous extra features, including auto-type on Linux, Windows and macOS, Twofish encryption, YubiKey challenge-response support, TOTP generation, CSV import, the already mentioned browser integration (with the use of a browser extension), and even a command line interface, among others.