Actually, if you want to go back even further... Jef Raskin of Mac fame created a programming language called FLOW in 1971 for teaching computer programming to humanities students. It's a cute little language (you definitely wouldn't want to implement anything significant with it) but he claimed that students who worked with it first did much better when introduced to "traditional" languages (BASIC, FORTRAN, etc.) than those who went in cold.

Among other things, it has the first implementation of what we would now call "autocomplete" that I know about.

If you're at all intrigued, I made a go at implementing the interface as described here: https://bitbucket.org/oofoe/flow

References at the bottom of the page. I actually contacted the Stanford University Library to get them to send me copies of his journal pages and papers so I could implement it.

Not sure it matters seeing as Facebook's Flow is already more popular. Good luck searching for "How do I [X] in flow" without getting more result for Facebook's Flow.

Even if Facebook's Flow never existed, the word "flow" is a challenging term to search for and was a poor name for both Flow9 and Facebook's Flow.

However, it was only open-sourced now, while FB Flow has been open-source for several years. It is actually kind of confusing considering both target JS.