Agreed, capabilities seem like a fundamentally better approach in basically all ways that matter. I should probably clarify that I mean "ACL" in the sense of "

Agreed, capabilities seem like a fundamentally better approach in basically all ways that matter. I should probably clarify that I mean "ACL" in the sense of "some kind of control, I hardly care what" since it's an easily-recognized term at least. And there probably will still be an ACL somewhere, e.g. to allow the library to use that eval at all, and then we trust it to pass capabilities correctly to others (or perhaps don't trust it! maybe I don't use that, and don't want it to silently appear later!).