[breck]

I don't think the Dumbdown prototype does that yet (haven't looked at the full thing in a while).

But inline links, bolds, italics, et cetera are super duper simple.

Tree Languages concatenate.

    markdown
     Someone can define a markdown
     node type and then you can just use markdown
     like you normally would *embed* _markdown_.
    emojiDown
     And this whole sentence would be bold if you added
     your own mini language, "emojiDown", which
     defined your own node types