jblow seems like a really talented developer. I loved Braid and there's clearly some great work being put into Jai. But if (and this is a big if) he wants to make Jai into a language people use, he should seriously consider putting more effort into the documentation and distribution side.
In addition to what other people have said, Blow is explicitly working on documentation over time and closed beta users have access to a fair number of documents detailing both language features and the philosophy behind the language.
One huge reason why the language IS still in closed beta is because Blow believes heavily in not releasing half-assed work. Documentation is a part of that.
That's a circular argument given what's discussed in this thread.
The "make or break them" presupposes the goal is for the language to "break out", whereas the parent said the goal is for the creator to be satisfied and use the language himself.
There tons of languages in domains like gaming where nobody cares if they "break out" or for network effects. People write them to use them themselves.
That is only one of the goals. The author is also interested in making that language public at one point, even if that comes as a far secondary concern for him, otherwise he wouldn't have bothered to publish anything.
"That's a circular argument given what's discussed in this thread."
What would you say to "whether anyone else outside of his company uses it is almost irrelevant"?
The compiler is not out yet, it's in a closed beta to a small number of developers with plans to release later this year (to the best of my knowledge).