Why I'm coding with Mithril
Presently, 58% of users of my current client's site arrive via mobile and minified React tops 145kb, which takes a lot of time to deliver and unpack. I serve 1000 new users per week who can't rely on finding React in their browser cache. This is too much overhead. I am a little obsessed with under-one-second loading and 3 second attention spans. Non-minified React is 642kb and that's too much code for me to grok if I want to understand what my application is doing.
Then I found Mithril. It's faster than anything. It's tiny. It does only what it needs to do, no bloat. And it does most of the good stuff that React does. It's also FRP friendly, another current obsession of mine.
It's in the early stages, but it is so small and focused that it can be used anywhere. TODAY. mithril.js is small enough to understand in detail. Beyond the basic documentation is a blog and API docs written as precisely and as focused as the code. It's a testament to its quality that the earliest blog entries are applicable today. I recommend reading them from oldest to newest. They read more like a tutorial than a blog. Post a question to the Google Group and Leo will likely refer you back to a blog post because he's already covered your question.
Another sign that Mithril is of great quality: most public discussion about Mithril revolves around the philosophy and logic of app design, not code errors. When errors are discovered, Leo patches them within hours if not minutes.
Leo got so much right. Most things right. More than any other framework I know.