Processing [1] is a language (/ ecosystem and IDE) that serves a lot of creative use cases, particularly creative graphics projects. Arduino re-used the GUI of the Processing IDE to build the Arduino IDE, which is called out on the startup splash screen for the latter, and is probably what you're thinking of.

An aside, I don't use Processing very often but every time I've dipped into it I've found it simple and enjoyable.

[1]: https://processing.org/