Chef you obviously had to, but my impression is that the DSL is so extensive you might as well be writing something that's not Ruby.
Maybe this says something about the power of Ruby, but I don't feel like these tools contributed to the language's popularity or ecosystem - definitely not the way RoR did.
This is just how Ruby is. It's designed around the idea of building DSLs, so writing in Ruby is almost always an exercise in writing in one DSL or another.
Now it's probably the third option, when building websites... and a fourth option, when building APIs.
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I don't think Ruby is a fad. The drop off Ruby had since early 2010s is dramatic, but it stabilized around 5% of all PRs on GH in the last few years:
https://madnight.github.io/githut/#/pull_requests/2023/2
It's still one of the most popular languages for web development.
But is it? Stats on major job boards such as Indeed show a steep decline in recent years. There are consistently twice as many Django/Flask roles listed compared with Rails. Node is the most popular but Spring, ASP.Net and PHP occupy the next level below Node.
I extremely doubt that. Maybe in your geographical area with small stage startups.
At any given time Spring has probably seen 10x usage of RoR.
Nothing against Plone (although I was very happy to put its foundation layer, Zope, in my rear view mirror). It's a fine program that's very good at what it was. But just because something's been around a while doesn't mean that it's still vibrant and growing.
Check out the charts from Google Trends some time.
Python was all over the place when RoR came out, meanwhile I only remember hearing about Ruby on random forum posts or by some enthusiast before RoR.
Outside of this, it's been perl and python, with python replacing perl after that whole perl 6 fiasco while the language and distros started understanding packaging python.
I had dabbled with Python before encountering it (in its embedded form), but once I started using it inside ESRI's ArcGIS software, it became my go to language for many, many tasks.
Then in about 2005 I heard about zope, and how easy and wonderful it was compared to php. But it was slow and memory heavy.
In about 2008 more and more stuff started getting python bindings, specifically in VFX (where I was working). There was a tussle between javascript and python, and python won out, even displacing MEL and other domain specific languages.
Ruby was always more obscure to me, it was for people that likes C and wanted a more perl-y version of it, but without the anachy or the universality of CPAN.
I think the biggest reason was that it had loads of stuff in the standard lib, way more than anything else at the time. Much more than perl, so it meant that things were a bit more "portable". So people came for the stdlib, then started adding things to it because they'd spent all that time learning it.
Python was popular as a teaching language, how it gained a foothold in academia.
I remember 20 years ago when I was starting out it was popular for game scripting (Lua was more embeddable but python was also used). plenty of first class interfacing methods to native code (still remember c++ boost shipping python binding generator).
Many tools shipped python as an embedded scripting language.
Python was used for creating build systems.
Not to mention any distro out there ships python, it replaced perl in that regard. Batteries included and being available helped it become the norm for random scripting.
Python was big before numpy/ML.