It was a series of experiments with new approaches to programming. Kind of reminded me of the research that gave us Smalltalk. It would have been interesting to see where they went with it, but they wound down the project.
LT was cool, but they abandoned it with insufficient hand-off when it was 80-90% done to work on Eve.
I know a bunch of people were unhappy that LightTable wasn't finished, especially because they raised money via Kickstarter for it.
Maybe Eve was too ambitious. Maybe funding never materialized. Maybe they just got bored and couldn't finish. Maybe they pissed off their audience.
It didn't get far enough to be "used" in a production sense. There was enough interest and people were playing around with it, but no real traction to speak of. Frankly, language projects are difficult because these days they have to be bootstrapped to a certain size before there's any appreciable use, and VCs are not patient enough for that kind of timetable.
Here's a postmortem Chris gave about all that: https://www.youtube.com/watch?v=WT2CMS0MxJ0 / https://www.youtube.com/watch?v=ThjFFDwOXok
As for me, I brought some eve-y ideas to my language project: https://github.com/mech-lang/mech