When I say "optional", I mean you can just create a filename.php and start putting lines of code into it, and it'll work fine. But, these days OOP is favored by most and pretty much everyone is using it. So if you are working on code that other people have written, classes are everywhere.
PHP is huge and more relevant than you realise. There are many many PHP developers.
IMO one of the things holding the fediverse back is that not much of it is written in Python or PHP. Neither are "good" languages but there is a massive pool of developers and they're easy to get up and running.
Often, the option to downvote is the only thing stopping me from getting sucked into some stupid argument with an idiot. It is a massive productivity booster. Downvote and move on.
I wish kbin would hide posts with lots of downvotes...
I tried a few different things in the kbin search and @intertwingled@tube.arthack.nz got a result that I could subscribe to. If that channel posts another video, it might show up in kbin. Will it be a microblog? A thread? A magazine? Who knows! kbin seems very confused about all of this.
I have heard of Mastodon instances with a dozen users using about 50 GB. So 40 GB for a single user should be enough, if you set up cron jobs to automatically prune old content. It depends how many people you follow and whether you set up a relay or not. (Single user instances without a relay kinda suck)
NB space on a VPS is usually a lot more expensive than space on S3 or equivalent. If you can configure Mastodon to store images on S3 it'll be more cost effective.
It's pretty complicated. Something like half the emissions / footprint of a phone or computer is in the manufacture of it so anything that means people don't need to replace their device is a win, regardless of battery life or power usage.
A lot of servers are run off renewable energy. If you check out the sustainability pages of AWS or Azure they both talk a pretty good game. Plus if you're using some flavor of serverless there isn't really a dedicated CPU core just for your app so sometimes the server side of it would be using zero energy as it's gone to sleep.
We really need to get to grips with how to measure the 'ecological weight' of software in a simple, reliable and transparent way.