Are there any modern closed-source programming languages?

At a recent OpenUK meetup, one of the participants declared that Open Source had comprehensively won. While businesses might not always release their proprietary source code, 100% of everything they wrote used an open source programming language.

I wondered how true that was. You can, perhaps, moan about the shenanigans around Java's licencing and you mutter about whether it is easy to get involved with C++'s JTC1/SC22/WG21 - but the core tech behind the two is open. Anyone can read the language specification freely and anyone can build a compiler legally.

It's the same with, to choose a random smattering, Python, F#, and even Apple's Swift.

Once upon a time, Flash ruled the roost. Now Flash is dead1. While COBOL existed before the term Open Source was coined, it is now an open specification with a GPL Compiler. Everything has become open!


There is still a stronghold of proprietary languages. MATLAB is still heavily used by mathematicians and scientists. Languages like R are Open Source and making great in-roads. But MATLAB is popular.

The K Language is widely used in financial firms.

Excel Macros, inexplicably, run the world.

Local scripting languages like AppleScript, and cloud languages like Google App Scripts are also closed - and can only run on proprietary software.

In the gaming world - while Lua and Godot and Blender are open - Unity is the big beast. And that's closed.

And, deep down in the silicon, the microcode running on your CPU, the blob in your Pi's multimedia decoder, and the baseband of your phone's modem are all locked down tighter than a whalebone corset.


Even in those closed gardens, the weeds of Open Source take root. There are hundreds of Open Source libraries, plugins, and tutorials for all proprietary languages. That doesn't get us to an open compiler or specification, but it brings the culture of Open Source with it.

So, has Open Source won? Mostly, I'd say. At the very least there are good Open Source alternatives to nearly every programming language and paradigm.

There are some niches - science, finance, gaming - which rely on proprietary languages. And Cloud services run custom software on their custom OS running on custom processors. The new paradigm of LLM AI might eventually be fully open, but rely on processing power so out of reach of mortals that it might as well be closed.

But as more and more students become aware of Open Source, I hope that those last bastions of jealously guarded code will eventually fall.

Got any more examples of proprietary languages? Join the discussion on Mastodon

  1. Flash may be dead but... 

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4 thoughts on “Are there any modern closed-source programming languages?”

  1. profande says:

    If Unity is the big beast then Unreal is the Leviathan, and it's sorta™


What are your reckons?

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