There's tons of static site generators out there, many of which are very powerful and offer a significantly larger breadth of options versus Ream. Quite a few of them have also been around for well over a decade. Why even bother writing Ream then?
In the end, it comes down to the right combination of features. My personal preference is against using Markdown or other markup languages to generate HTML. HTML itself is already a markup language and it's not only straightfoward, but also much more predictable in the produced output. It's also very human-readable1 — when it's been written by a human in the first place.
The other big factor is templating languages. Complex templating languages with looping, conditional constructs, and abstract data referencing are very popular. My goal was to write a static site generator that let the user focus on writing their site, not fiddling with templates. In the end this means that some more advanced things aren't possible and they might have to do a tiny bit of copy-pasting. I think the reduced mental overhead is worth it though, especially for personal websites.
Waxing Poetic
My philosophical motivation behind this whole thing is because I grew up during the rise of the Internet and the blogging boom. I remember the sorts of weird, personal things that people used to put on the internet before the rise of social media. I don't think we'll ever make it back there, but we might as well try and at least we'll make some cool stuff on the way.
I also remember how easy it was for anyone to just get a small space to call their own and put up a blog or hobby site. Social media has taken away personalization and with it free expression. It has commodified us all; we're merely content creators. With Ream, I'm hoping to do my part to help us all get back to the future we were promised and away from the one that was forced on us.
1. Ok, I'll admit that HTML entities are kinda annoying to deal with and a bit surprising for beginners.