I just published prejsx, a simple JSX-to-html transpiler for Rust. it supports evaluating basic math expressions with prejsx_math.
Example
use prejsx::render;
fn main() {
let input = r#"<h1 className="title" style={{color: "blue"}}>Hello {2 * 2}!</h1>"#;
let html = render(input);
println!("{}", html);
}