I don't have details about that software, but there was something which I remember from the early 90's or so: software our church had for clerks -- "MIS" for membership info, and "FIS" for finance. A clerk would use one or both of those weekly or more, and they fit the above description perfectly. I missed them when they moved to a graphical UI.
Similarly, I always thought the UI of "git commit --interactive" was at a sweet spot of being both helpful and efficient, once I got used to it.
(All the above inspired the UI of the knowledge manager I wrote/provide at http://onemodel.org -- AGPL, I use daily and rely on it for many things, currently requires user to perform postgresql installation & upgrades; hoping to move to sqlite someday, when health allows. But most people, especially non-keyboard-oriented people, probably wouln't like its UI. It is perfect for me: very efficient/effective and everything you need to know is on-screen.)
And vim & tmux are things of beauty, after the initial investment (ongoing, for vim).