For almost as long as I've been programming, I find Ocaml a fantastic language, which just lacked some development tools and improved concurrency. I still believe that under the right circumstances it could become a mainstream language.
Comparatively, OCaml was initially written with symbolic operations in mind, and thus I personally think it's a great language for writing parsers, compilers, modeling systems etc. The type system makes it easy to avoid certain kinds of common errors in those programs and the tail latency of GC operations is typically not as important for those applications as overall throughput. I don't think that heavy symbolic computations are a mainstream target though. To be clear I think that's absolutely OK for a language not to aim for mainstream use; but if one wishes for mainstream use, then it's important to be clear about the kinds of use-cases within mainstream that will be targeted.
It has been a while since I played with the language though, so maybe things have changed since. Happy to learn more if I'm wrong and OCaml now has a clear mainstream target use case in mind.
Sure, OCaml's heritage is descended from a theorem prover helper language, but that doesn't meant it's forever stuck at that use case. Python was originally an educational teaching language, nowadays it's a data science and glue language. None of that was planned out in advance by the Python folks.
In fact even if you ask the Go team, Go is arguably the most targeted language of the ones you listed, in terms of its use case--and they were surprised that a lot of their userbase came from ex-Python devs who wanted something more reliable and efficient!
OCaml with version 5 is just hitting its stride. With the advances in the language, the multicore support, and tooling, it's going to be competitive with Rust for many use cases. It's worth the wait to see where it goes.
Java was an OO, garbage collected language that supported (sort of...) hot swapping code. Go was a reasonably performant, garbage collected language that compiled to static binaries and has great cross-platform support. Some grad student decided to write Spark in Scala so you had to use it for Spark jobs Rust is a systems programming language with zero-cost abstractions and no GC that allow you to write mostly memory-safe code.
What is the killer feature of OCaml that makes it worth the investment?
Does checking the concurrency box make OCaml an awesome choice for some use case?
You mention Rust for example but that language is sort of built around a zero cost abstraction principle, which is very much not the case of OCaml, so I still think it's going to be viewed as risky for highly performance sensitive work.
For truly performance-sensitive work of course people are going to choose C/C++/Ada/Rust.
Mainstream languages have killer software (Spring, Synfony, Pandas, whatever) which then prompts adoption.
Languages for mainstream programming are less of an issue than the software.
Haskell, CommonLisp, etc, plenty of great languages lack that killer software or clear benefits over other mainstream languages.
Same thing for Spring. Spring came about as an attempt to make J2EE more usable, which is to say, it didn't exist until years after Java was already being widely adopted in the industry.
Checking on Symfony since I'd never heard of it, it was first released in 2005, which was after PHP had already become popular enough to become the archetypal "bad language" in the minds of people who had never used it.
I think what you're seeing is that the ecosystem that develops around languages reflects their popularity and the interests of their users. As a readable, low-complexity glue language, Python became popular with scientists and then (unsurprisingly in retrospect) people started using it for data analysis. Java became popular with big iron enterprise programmers, and so it sprouted enterprise frameworks where half your code was in XML. PHP was popular for small web sites, so it spawned a whole menagerie of web programming frameworks. A language without any ecosystem growing around it is probably a language that doesn't get used much.
For a more contemporary example of language adoption, look at Rust. The appetite for the language existed from the get-go based on its design and stated goals. There was a lot of excitement, even from people who said they couldn't adopt it yet because of the lack of ecosystem around it. As the ecosystem developed, more and more people adopted it the moment it was practical, establishing it as a mainstream, growing language prior to the existence of any killer software. In the future maybe there will be a killer Rust framework that brings in a lot of people with no interest in Rust the language, but Rust is thriving despite that killer app not existing yet.
Sometimes the language is chosen by luck (e.g. company requires it) but many times a programmer will make an explicit choice to use that language.
They accepted to place it on the box, but never gave it the same love as VB and C#, or even C++/CLI, and now they could rename the Common Language Runtime into C# Language Runtime, given how little outside they give to anything not C# on newer workloads.
Had F# been given feature parity with C# and VB on Visual Studio tooling and core frameworks, the adoption scenario would be much different.
Previously it added a lot of stuff on its own like async, etc. which was cool but also resulted in compatibility issues when c# later added similar features.
Now the f# developers are very concerned with compatibility but it basically means that f# can't get new features until c# already has them. It's also limited by the runtime which is designed around c#.
For example, it doesn't support type classes because (among other reasons) that might end up being incompatible with future c# type-class like features several years down the line.
It's also hard to learn f# unless you already know some ocaml/haskell.
ocaml has failed to catch on that much so far but I think it does have potential, and adding multicore support/effects is pretty promising.
On the other hand the fragmentation with stuff like reason/rescript is pretty dumb.
That's my impression from my last two typescript jobs, anyway. I don't know what, if anything, will come out of this, but I can't see it being bad.
I know the syntax is now incompatible syntax with OCaml so I see the broken eggs but I don't see the omelet.
Reason seems to be pretty dead so now the relationship between ocaml and rescript is kind of like that between haskell and purescript.
This may be good if you only want to run it on the frontend but it's not as good if you're using ocaml on the backend and want to share code, but I guess there's js_of_ocaml
I also don't think the existence of rescript is in itself a bad thing, it's just that the whole confusion around reason/rescript may have harmed development of ocaml for a while.
OCaml is an anchor language for many important projects (e.g. Coq) and companies (INRIA, Janestreet etc). The momentum behind OCaml has grown and I don't think the rescript/reason separation affected it _that_ much.
But I am curious to know if rescript/reason issue harmed rescript. While rescript gained a lot of technical freedom from the breakaway from OCaml it lost some people along the way. Was the breakaway worth it in retrospect?
Personal anecdote: yes, it has.
I was very interested in Reason when it appeared, and it seemed to have immense momentum: exploring arguably better (or more familiar) syntax, tool integrations etc. I know that people ran regular OCaml workflows/projects with it.
And then the whole split happened ... why? "We don't want to be constrained by OCaml" while keeping all of OCaml's syntactic idiosyncrasies among other things doesn't sound like a proper, well, reason.
This is where I stopped being interested (and as I imagine, many people stopped, too). Because a slit in a niche miniature language (which it was at the time) means only one thing: not enough resources to continue with either one.
It doesn't help that the whole split was confusing to everyone. Good description here: https://ersin-akinci.medium.com/confused-about-rescript-resc...
A lot of talent has moved onto other things (or stayed with Reason) with arguably minor gains for Rescript in terms of technical freedom gained.
Typescript is so dominant in this space that it really didn't make sense to split an already small community.
F# is an interesting language and yes, I used it at work a couple of times. However finding a programmer who is into that is hard and the HR "partners" will kill you because people like these can't be treated as cheap replaceable resources. So it was F# prototype -> C# production. Attempts to introduce a new language or a tech stack usually failed because the decision makers (managers) were concerned about "how many people can I hire within a month" than anything else - nobody was fired for picking Java, C# or JavaScript (TypeScript) for the next project and staffing accordingly.
Languages like OCaml, Haskell, Lisp (whatever flavour you pick) or Prolog will never become mainstream. Should they even? My favourite is one of them for my general hacking or research projects; not sure I'd like to use it in a corporate job (which I have right now). Small efficient team in a tech start-up? Hell yeah! Mainstream mundane programming? OMG NO! Horses for courses. Hearses are not mainstream vehicles yet all of us will need a ride in one occasionally. Does it mean they should become popular and mainstream? :-D
Regarding Ocaml, the functional aspect of the language is not hard. I have trained several junior programmers to write code in it (ReasonML). It is not a pure functional language. The biggest challenge for most people is dealing with types.
Ocaml's standard library is a huge sore point. It also lacks a lot of proper tooling. The biggest problem with Ocaml/ReasonML is that they are unable to rally everyone to a unifying vision to gain traction.
Nowadays C++ has closures. What will become the FAD of the day in 10 years? Will wee see embedded Prolog in C# 12 or C++31? Who knows? Like OOP has been with us since 1968? and hasn't disappeared anywhere, functional programming features will not disappear from mainstream languages. But the "cool new shiny silver bullet" will be something else. Like Simula-68 and Smalltalk-80 paved way for OOP, Haskell and OCaml (et. al.) have been paving way for functional programming and Prolog and Datalog have been paving way for logical programming. They won't become mainstream when logical programming becomes the FAD of the day.
BTW you mentioned you taught a couple of junior programmers an ML-ish language. That's awesome! We all (programming community) need more legends like you.
By definition, fad is an intense and widely shared enthusiasm for something, especially one that is short-lived; a craze. I don't see OOP enthusiasm to be short lived.
Many are still living in the Kingdom of Nouns, are follow Uncle Bob's preaching with due diligence and judge you harshly if you don't make everything a class and don't use lots of design patterns even if they are not needed.
Without verdict about what else you wrote: What a fitting description, "kingdom of nouns". I'll steal that for my next anti-mainstream-OOP-everything-must-be-a-class-rant, if you do not mind.
I think this is a bit overstated. It's roughly the same size of JavaScript, missing regexes but having some stuff that JS lacks. And in lots of languages with large standard libraries, people tend to use standard library replacements. Considering that htere are also not a lot of people working on OCaml, the core team time is better spent on stuff like multicore rather than HTTP servers and clients.
The standard library is also open to contributions. For example, in OCaml 4.14, 44 functions were added in the module Seq https://v2.ocaml.org/api/Seq.html. String also had a lot of utility functions for integer decoding in 4.13 https://v2.ocaml.org/api/String.html.
Kotlin is a Jetbrains project and it certainly didn't hurt that Google made Kotlin the preferred language over Java for development on Android, and that Kotlin itself has great Java ecosystem compatibility.
For years, Rust was Mozilla's baby, and they did a lot of good work evangelizing Rust for its use case, and other companies adopted it as well, continuing the cycle.
There is nothing I can think of that is comparable for F#, OCaml, Haskell and many other fine languages
PHP was "easier" Perl. Perl was also ubiquitous at one time because of CGI and the web. PHP was one of the first languages to have the same ease of deployment story as Perl but a much easier syntax to deal with. Again, language space wasn't as crowded then. Certainly both were easier to use than C / C++.
It was easier to gain a foothold in the first round (web 1.0 era if you will) of software and development. There was simply less competition. Java didn't even come out till 1996.
The second era of languages, I think really starting with Go and continuing through to Rust, they faced a bigger uphill battle. There simply isn't the mindshare to capture as easily as there was back then.
Admittedly, I'm still not sure to this day why Ruby took off, other than it offered a great developer first experience as a language, from what I understand. It seems people who use Ruby tend to really like it. It seems it has a stickiness there that other languages don't, maybe? I've always been confused by this one, and I admit that's due to personal bias of not enjoying its syntax at all, however there are clearly lots of people who do. I just prefer one true way of doing things.
[0]: https://www.embarcadero.com/
[1]: https://www.embarcadero.com/products/delphi/object-pascal-ha...
CERN and Fermilab were already playing with Python as administration tool and data analysis during the early 2000's.
PHP became mainstream thanks to being a better Perl for Web applications, and the only option in many ISPs.
Ruby has Rails to thank for its adoption, a product produced by Basecamp.
Ruby I'm not sure what caused the hype unless it was something like Heroku making deployable Rails easy.
Youtube, Instagram, Pinterest, Reddit etc.
Now I know correlation does not equal causation. But you have to think it must have some effect when Google is paying its Distinguished Engineers--the likes of Rob Pike, Ken Thompson--plus at least several more engineers, project managers, and others. All to work on Go. Can you imagine what the OCaml ecosystem could do with that kind of money and dedicated engineering talent? Heck, any technology for that matter.
Idk about that, especially in the past decade. Python seems to be the most popular language that people pick up on their own as their first one.
As for the intro college courses for programming, they mostly seem to be Python or Java, with occasional C (havent seen that one myself yet for an intro class), and one incidence of OCaml (apparently Cornell teach their intro to CS in it).
https://en.wikipedia.org/wiki/Generational_list_of_programmi...