I had encountered sqlcl before, but it requires the JVM, and I don't believe it is open source. With usql, it's open source (MIT), already works with more databases than sqlcl does, and very soon I will have built releases for Windows, OSX, and Linux that one will simply be able to download a single, relatively small (roughly 8 megs) binary and be able to work with any SQL database using the exact same command-line interface for each.
It doesn't require Go any more than nginx requires C. Go executables are for the most part static, and depend on very little, making them highly portable across distros.