There are many reasons why there are not many PL startups. From my perspective--as a PL tool developer for 40 years--is that we still do not have reliable forma

There are many reasons why there are not many PL startups. From my perspective--as a PL tool developer for 40 years--is that we still do not have reliable formal grammars that describe the syntax and static semantics for a given programming language. That is a crux because it is difficult to write a tool for a language when we cannot even define what that language is. When you ask where to find a grammar for the language, the default answer is to just use an "official" implementation. That often requires a large amount of time to find and understand an API--and then locks you into that implementation. Some of the popular languages publish a grammar derived by a human reading the implementation after the fact, prone to errors. For C#, the standards committee is still trying to describe version 6 of the language (https://github.com/dotnet/csharplang/tree/main/spec https://github.com/dotnet/csharplang/tree/main/spec), and we are now on version 10. An Antlr4 grammar for C# is mechanically reverse engineered from the IR, but it does not work out of the box--it contains several mutual left recursions and does not correctly describe the operator precedence and associativity. Julia does not even have a formal grammar published for the language. You cannot easily refactor a formal grammar from something that does not even exist, and have to write it from scratch. Often, what is published is out of sync from the implementation, not versioned, tied to a particular parser generator and target language with semantic predicates. The quality is suspect because you are unsure whether it even follows a spec. No one bothers to enumerate the refactorings involved in modifying the grammar to fit a parser generator, or for optimization, e.g., speed or memory. Yes, I can agree: “[t]here's definitely a need for SOMETHING, as developers have so much pain.”