The most actively developed of the Mono-free KeePass2 ports to Linux. Open source. Qt, yet somehow manages to be ugly anyway.
KeePassXC is a fork of the earlier KeePassX. Their GUIs appear identical, which is not a good thing. Like the entire KeePass family, usage is clumsy: launch, provide master password, and you have an unattractive list of entries. Highlight the one you want, then use keybindings you have to memorize to copy to the clipboard URL, username, and password. It gets the job done but it’s neither attractive nor pleasant to use.
The basic features (don’t know about advanced features) are intuitive, but there’s no documentation at all.
Like the rest of the KeePass family, no native sync. Proponents glibly say that you just plop its live database into your sync service of choice. I am a support engineer for a popular sync service and have worked first hand with people who have done this and have gotten a corrupt KeePass database for their trouble. Pointing any general purpose sync service to a hot database is an exceedingly bad idea and the only surprise for me is that it sometimes works.
A maze of twisty little passages 