Do you have sources you could point to? I once read that it's a great language mired by a designed by committee ecosystem. I really liked the language when I tinkered with it a bunch around 2010 but moved on after work pushed me to other languages like C# for GUI stuff. First language I used with simple built in concurrency.
For my safety-critical automation software for a machine that will operate around people and overhead, I’m choosing Ada/SPARK2014. Its decades-long track record in high-integrity domains like aerospace, defense, and medical systems ensures reliability for applications where human safety is paramount. SPARK2014’s formal verification tools mathematically prove the absence of runtime errors, aligning with standards like DO-178C and ISO 26262, critical for my Q3 2026 market deadline. While Rust is gaining traction for memory safety, its formal verification tools, like LEAN/Aeneas, are still maturing and lack the production-ready ecosystem of Ada/SPARK2014. Ada’s clear, structured syntax simplifies code reviews, and its tooling generates certification reports familiar to regulators, streamlining approval processes. For my project’s safety and business needs, Ada/SPARK2014 is the proven choice - for now. I am not a fan of Rust syntax or complexity, but that is somewhat subjective. I last dove in about 2 years ago.
This is effectively a fork of the Rust Reference, made by Ferrous, and laid out in a way that allowed the compiler to be qualified. It now lives at this URL, because it's being adopted by upstream as the spec.
Sounds like progress is being made on the language spec front, that's good to see.
I'm not following what you meant by this though, it seems like a contradiction:
> A language specification is not required to be qualified. The behavior of the compiler needs to be described.
But they're putting work into reviving the language spec, to enable certification? Also, if the source language hasn't been described, then surely the compiler's behaviour hasn't been described.
Or did you mean that their documentation is for the Ferrous flavour of Rust and might not reflect the latest version of the Rust language?
It has already been qualified. Upstream has always wanted a spec. It’s being worked on because it’s desirable, not because it’s blocking safety critical cases.
You’re always going to need to have more than a language spec because you qualify compilers not languages.
> Also, if the source language hasn't been described, then surely the compiler's behaviour hasn't been described.
It has. At least to the degree that regulators find it acceptable.
> Or did you mean that their documentation is for the Ferrous flavour of Rust and might not reflect the latest version of the Rust language?
There is no difference in flavors, but it is true that each version of the spec is for a specific version of the compiler, and so sometimes that will lag a bit. But that’s just how this process works.
Yes, but a qualified compiler is but one of many pieces in having an ecosystem/tooling for creating, testing, and having high-integrity applications reviewed and certified. A couple of the industries we are elbowing in on, are already familiar with the type of reports generated by the AdaCore tooling. Ada has a decades-long history in safety-critical systems (e.g., Boeing, Airbus, NASA), with proven reliability in real-time, embedded applications.
AdaCore’s GNAT Pro suite includes qualified tools (e.g., GNAT Pro, CodePeer, GNATcheck) that support traceability, code coverage, and certification evidence for standards like MISRA, DO-178C, and EN 50128. These are battle-tested in aerospace, defense, and medical applications.
Ada is defined by an ISO standard, specifically ISO/IEC 8652. The latest revision, as of 2025, is Ada 2022 (ISO/IEC 8652:2023), which includes updates to the language features. Ada is also recognized as an ANSI standard through its adoption by the American National Standards Institute, aligning with the ISO specification. The standard defines the language’s syntax, semantics, and features, ensuring consistency across implementations including compilers.
Rust’s safety guarantees prevent many runtime errors, but its approach relies more on programmer discipline vs. Ada/SPARK2014's "correct by construction" methodology. Ada is designed for real-time systems, with built-in features like tasking, protected objects, and precise control over timing (e.g., Ravenscar profile), optimized for cyber-physical systems.
Excuse my verbosity, but I pulled a few things from our tech pitch deck, and a little of the above is in our business plan as well that I copy/pasted.
Two great books if you're interested:
Analysable Real-Time Systems: Programmed in Ada (2016)
Building High Integrity Applications with SPARK (2015)
Ah, I thought we were talking about the language, not the broader way it fits into everything else.
I am familiar with all of this stuff :) I think you may be under-estimating Rust a bit. But that’s fine.
Incidentally, you can also get a Rust qualified compiler from AdaCore. I haven’t kept up with what specific standards they’ve qualified it against though.
That's for automotive. We're shooting for a bunch of various relevant standards. There is no formal language spec. Who did that compiler? AdaCore's been around for a long time, so I am quick to use theirs if I were to chose Rust. I'm also following the Ironclad kernel project with its complementary OS called Gloire. Ada/SPARK for both with partial formal verification progress.
Automotive is the first industry that’s really taking up Ferrocene! They’re adding more stuff as more industries have demand for it.
Ferrous and AdaCore were originally collaborating, but then they parted ways. In my understanding they’re both largely the upstream codebase, I know that the Ferrous folks religiously upstream almost everything, no clue if AdaCore does as well.
I am excited Rust is heading in this direction. We had to go with SPARK2014/Ada (2022) when we made this decision over a year ago. Rust and its tooling was and is not ready for the safety critical control system we are developing. High-integrity, safety-critical auditors in government and industry are already aware of the types of reports generated by the AdaCore tooling, so this makes less friction in seeking these certifications. We are also hoping the Ironclad Kernel and Gloire OS gain traction. A kernel written in SPARK2014 and fully formally verified and a complementary OS using Ironclad would make it turtles all the way down to our bare metal controller up to the control system application and HMI. I will certainly keep Rust on my radar in the future. Do you have any examples of where Rust is mainly the PL used in a CPS (Cyber-Physical System) that requires this level of integrity and safety? SPARK has applications in avionics and other industries that go back for decades: Typhoon EuroFighter - flight control and mission-critical systems; Harrier GR9 - avionics; UK NATS iFACTS System - safety-critical air traffic control software; LifeFlow Ventricular Assist Device - medical device to support heart function. SPARK was used for its control software, and the list goes on and on.
Can you point to a production language today that doesn't have a committee leading it's development?
C, C++, Rust, Javascript, Python, etc. All have committees leading their development. The only difference with Ada was that, for a long time, that committee was in the DoD (which has plenty of fine engineers, given it's practical achievements) instead of ISO/ANSI. And instead of being focused on general purpose, they had a clear domain they prioritized. That's different now, but it's hard to erase a few decades of heritage.
Specifically, I think these three paragraphs near the end are critical:
> I'm reading a great book now called Why People Believe Weird Things, by
Micheal Shermer, in which the author explains what rational thinking is,
and how skepticism is a process. Basically, people believe something
because that want to, not because of any scientific arguments you make.
> There are guys out there who dislike Ada, but they do so because they
want to, not because of any rational analysis of its merits or flaws.
Sometimes even their arguments are factually incorrect, like saying that
"Ada was designed by committee," ignoring the fact that Jean vetoed
language design arguments that were 12-to-1 against him. It's not
unlike creationists who explain the "fact" that evolution violates the
2nd law of thermodynamics. (No, it does not, as any book on freshman
physics will tell you.)
> I've explained the reasons Ada why I think is not as popular as C++, and
I'd like to hope that it will convince Ada's detractors that Ada isn't
so bad after all. But as Robert Dewar pointed out, a person who has
made an irrational decision probably isn't going to be swayed by
rational arguments!
That is, people aren't really rational. A choice was made to dislike it, it entered into the culture and to this day people dislike it because they think they should dislike it. They don't even spend 5 minutes studying it to see that half of what they've heard (if not more) is flat out wrong. In several Ada discussions on HN people claim its syntax is like COBOL's, for instance. Not just similar in being keyword heavy, but practically the same. Sometimes they even provide Ada "examples" that won't even compile. That's the kind of nonsense that happens when people turn off their brains or refuse to turn on their brains. You see it in many Lisp discussions as well.
There may be lots of uninformed post-hoc rationalizations now, but it couldn't have started with everyone collectively deciding to irrationally dislike Ada, and not even try it. I suspect it's not even the ignorant slander that is the cause of Ada's unpopularity.
Other languages survive being called designed by committee or having ugly syntax. People talk shit about C++ all the time. PHP is still alive despite getting so much hate. However, there are rational reasons why these languages are used, they're just more complicated than beauty of the language itself, and are due to complex market forces, ecosystems, unique capabilities, etc.
I'm not qualified to answer why Ada isn't more popular, but an explanation implying there was nothing wrong with it, only everyone out of the blue decided to irrationally dislike it, seems shallow to me.
"Am I out of touch? No it's the children who are wrong."
This argument eats itself. It's just an accusation that people who disagree with you are irrational, and their arguments are in bad faith. It's not a valid argument because it doesn't even depend on any context or facts of the actual discussion which he's using it. It's the definition of cope.
In the end, even if we can't be sure why Ada failed, it failed spectacularly. It had massive institutional backing and never made it past obscurity. I don't know exactly why people dislike it so much, maybe because everyone already knew C, C was well supported, every single OS was written in C, etc, so trying to bring some incompatible algol like language (always a popular lineage hahaha) with very sparse to nonexistent tooling and very theoretical advantages, especially considering the huge performance disadvantage at the time on highly constrained resources of computers at the time was not likely to succeed on its face.
The only exception I can think of is early versions of mac os, which was still primarily assembly. Even then i recall people went out of their way to use C despite needing pascal calling convention for system calls. They basically immediately regretted using pascal and started a march towards C and basically gave up on pascal before the powerpc.
So Pascal had one mainstream OS for about 10 years, most of which time it was being phased out.
> which os was written in Pascal? most were written in assembly in that era, you are talking about some obscure research or toy.
Your first claim: Every OS was written in C. Your new claim: Most were written in assembly.
Pick a position. If most were written in assembly then it would not have had any impact on the adoption of Ada so why make the original claim?
I would respond to your question but you substantially edited your comment and removed the question. I also notice you removed the claim in your edit about most OSes being written in assembly in the 80s. Obnoxious way to communicate with people, altering your comments while they're replying so their replies look like random comments.
> They basically immediately regretted using pascal and started a march towards C and basically gave up on pascal before the powerpc.
Nonsense. MPW Pascal and Think Pascal were well supported developer tools, and a lot of third-party developer code was written in them during the 80's. Photoshop (1987) was originally written in Pascal! Apple's Pascal dialect had object extensions that made OOP simpler than with C or standard Pascal.
Pascal started to leave the building circa 1991, when C++ became viable for OOP. Even then, Metrowerks CodeWarrior supported native Pascal compilation for PowerPC in 1993/4.
> It is in this context that Assistant Secretary of Defense (Command, Control, Communications, and Intelligence) Emmett Paige, Jr., requested that the National Research Council's Computer Science and Telecommunications Board (CSTB) review DOD's current programming language policy. Convened by CSTB, the Committee on the Past and Present Contexts for the Use of Ada in the Department of Defense was asked to:
> * Review DOD's original (mid-1970s) goals and strategy for the Ada program;
> * Compare and contrast the past and present environments for DOD software development; and
> *Consider alternatives and propose a refined set of goals, objectives, and approaches better suited to meeting DOD's software needs in the face of ongoing technological change.
> Paige says he believes industry engineers will be more likely to accept the benefits of using Ada if DOD leaders recommend, not require, the language. Software engineers, who would rather choose a language based on its merits rather than because of a governmental mandate, historically have resisted the Ada mandate on principle.
and
> Chief complaints about Ada since it first became a military-wide standard in 1983 centered on the perception among industry software engineers that DOD officials were "shoving Ada down our throats."
This is basically the story: The DoD tried to mandate it, people resisted, and made liberal use of the ability to be granted an exception, and so they eventually gave up.
The first link contains much more nuance, some excerpts:
> In decisions affecting adoption of programming languages, non-technical factors often dominate specific technical features. These factors include the broad availability of inexpensive compilers and related tools for a wide variety of computing environments, as well as the availability of texts and related training materials. In addition, grass-roots advocacy by an enthusiastic group of early users, especially in educational and research institutions, often has broad influence on adoption of programming languages. These advantages were largely absent when Ada was introduced in 1980. In contrast, C++ and Java both have achieved widespread acceptance and use. The strong military orientation of the publicity generated for Ada also may have served to alienate significant portions of the academic and research communities.
> Ada has not been widely taught in colleges and universities, particularly compared with Pascal, C, and C++; until recently, even the military academies taught programming in languages other than Ada
> Historically, compilers and other language-specific tools for Ada have been significantly more costly and slower in coming to market than those for C and C++.
> Software engineers are likely to be interested in enhancing skills that they expect to be most valuable in the software engineering marketplace, which is now dominated by commercial opportunities. Thus, programmers have moved quickly to learn Java and Hypertext Markup Language (HTML; used to develop pages for the World Wide Web) because they see these as the next wave, which can carry them to new career opportunities. Similarly, software engineers might avoid using Ada if they see it as limiting their careers.
Do you have sources you could point to? I once read that it's a great language mired by a designed by committee ecosystem. I really liked the language when I tinkered with it a bunch around 2010 but moved on after work pushed me to other languages like C# for GUI stuff. First language I used with simple built in concurrency.