I use xombrero in OpenBSD and believe that it will still function in the upcoming release - 6.0. That said, it just broke in OpenBSD current and Debian testing. The breakage appears to have something to do with webkit/gtk3. In the past, the OpenBSD, webkit maintainer had to invest a significant amount of time getting webkit-gtk3 to work.
So coding options appear to be to fix webkit-gtk3 or adapt xombrero to the latest webkit based on gtk4.