Careful, though: WriteFreely is solid, but limited.

For example, it has no comments. Like, there's no way you can interact with a WriteFreely post, at least none that the author would notice. Comments are planned, but way down the to-do list.

Also, while you can embed images, you have to host them externally and then hotlink them. I think this is one of the next things that WriteFreely will tackle. It's possible; Plume has its own built-in image hoster, but Plume is so underdeveloped that its devs recommend WriteFreely instead.