Rado was conceived of by myself (alercah) shortly after the SM/ALttPR combo randomizer release An earlier design of Rado treated links as first-class entities, and didn't have a concept of actions. After a surge of interest, largely from the SM/ALttPR combo randomizer community, and especially @gjgfuj, it was redesigned around the concept of actions, which made the language more complex but also resolved a lot of the outstanding design issues.
Earlier versions of Rado had a syntactic sugar of multi-item and multi-location declarations which allowed declaring multiple items and/or locations with common properties quickly. As it became clear that significant revision was needed to the core language, and more cpomplex semantics, it became clear that syntactic sugar was a problem for later.
The new version includes a lot more in the way of tools for code reuse and modularization, in particular, the ability to build on top of an existing project by modifying it. It has a lot of new (to me, anyway) ideas, including the first-stage compilation model that focuses on a highly declarative style with overrides, designed to have powerful flexibility and expressiveness without creating ambiguity or confusion. The focus on commutativity is particularly important. This component of the langauge, if it proves successful, may be valuable in other contexts such as configuration languages.
Rado was formerly called Peri; the name was changed after it had developed negative conntations with something in my personal life (unrelated to the language).