Gel: Modern Gem manager and Bundler alternative (Ruby) (github.com)

This looks like an interesting project but it doesn't look like it's been updated in a couple of years.

I'm always leery of swapping to new replacements for well established tools for this reason; what will support look like in a few years time?

You may have a temporary speed advantage over the incumbent but will the incumbent be able to catch up and provide regular updates?