I give micro.blog a C- on code formatting. The code block is monospace, but has no highlighting applied. The code block is wrapped in <pre> and <code>, with the language captured as a class within code. That’s enough to get a javascript syntax highlighter to work, but I’m of the firm opinion that syntax highlighting should be a server-side operation. The lexer should wrap each language token in a CSS class, and let a stylesheet colorize the syntax.