If the first question you’re asking yourself looking at a code base is “what version is this/do I know this version” then that language is not facilitating you.
The successful languages are ones where “the community” prioritises backward compatibility. Java, C, Python have backward compatibility spanning decades. There’s a few discontinuities (lambdas in Java 8, Python 3, C++) but in most cases there’s a clear mapping back to the original. Python 3 is an exception to this but the migration window was something like 15 years…
Busy engineers, scientists and academics have little interest in keeping up to date with language features. A computer and a programming language are a tool for a job and the source code is just an intermediate artifact. These are your “community”, and the stakeholders in your success.
I dunno it was 20 years ago I jumped ship when they tried shoehorning object oriented semantics into it. Eugh.
Doesn't mean I have to deny them the right to exist because they don't have a "community*".
* more like a religion for some programming languages.
Perl6 had been renamed to new language, Raku.
This can in turn fuel development of the platform therefore helping keep it relevant.
In recent times we call this “the network effect” and it applies to more than just social media.
from __future__ import annotations
requires-python = ">=3.9" $ python3.13 -c 'from __future__ import awesome_feature'
File "<string>", line 1
SyntaxError: future feature awesome_feature is not defined
Anyway, I'd guess what they intend is
try:
from __future__ import fever_dream
except SyntaxError:
fever_dream = None
use v5.40;
....
(I'd argued for that feature for years with my `Modern::Perl` feature bundle; glad to see that can be deprecated now.)
A major new version of Perl ships regularly. A few weeks ago the latest major new version shipped. From the 2025 changes document:
> Perl 5.42.0 represents approximately 13 months of development since Perl 5.40.0 and contains approximately 280,000 lines of changes across 1,600 files from 65 authors.
Skipping back 5 major new versions (to 2020):
> Perl 5.32.0 represents approximately 13 months of development since Perl 5.30.0 and contains approximately 220,000 lines of changes across 1,800 files from 89 authors.
2015:
> Perl 5.22.0 represents approximately 12 months of development since Perl 5.20.0 and contains approximately 590,000 lines of changes across 2,400 files from 94 authors.
2010:
> Perl 5.16.0 represents approximately 12 months of development since Perl 5.14.0 and contains approximately 590,000 lines of changes across 2,500 files from 139 authors.
There's been well over 10 million lines of code changed in just the core Perl codebase over the last 25 years reflecting huge changes in Perl.
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Perl 6 ... isn't backward compatible
Raku runs around 80% of CPAN (Perl modules), including ones that use XS (poking into the guts of the Perl 5 binary) without requiring any change whatsoever.
(The remaining 20% are so Perl 5 specific as to be meaningless in Raku. For example, source filters which convert Perl 5 code into different Perl 5 code.)
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But you are right about one thing; no one you know cares about backwards compatibility, otherwise you'd know the difference between what you think you know, and what is actually true.
What the hell is this? Even if nobody I know cares about backwards compatibility, how does this relate to whether my knowledge is true or not?
Apologies for trivializing perl5's progress in the past 25 years, but come on, chill out dude.