Any good javascript BBCode parser?

I haven't personally used any Javascript BBcode parsers, but the top two Google results (bbcodejs and this blog post) seem pretty weak. The former only seems to support simple find-and-replace, and the latter seems to have pre-set BBcode built in, so you'd probably have to hack it a bit if you chose that solution.

Your best options are probably to roll your own solution (possibly basing your work off one of the two links here), or just use AJAX and move on. That's probably the best way to ensure that previews are accurate, and previewing doesn't have to be real-time on every keypress, anyway; a delay before even sending the request is acceptable.

It is a bit late, and the question has certainly been answered. However if you are still open to suggestions, and have not yet spent your time converting the indicated parser from C# to JavaScript, I have written a parser (originally in PHP) which I converted myself[2] to JavaScript. It is available at bitbucket under the 3-clause BSD license. The parser seems to be reasonably fast, but I haven't performed any analysis on its speed.

It may not be as flexible in some ways as other possible projects out there, but it does allow defining your own codes ("bb-code" or not, with quite a few properties), and is also all contained within the one file. This is not a simple find-and-replace parser, and is not based on regex.

If this is of any interest to you, it might save you from having to convert that other library. Technically, I'm a relative "unknown", but that's the great things about JS/OSS: you can check out the source to see what I've done.

[2] As a result, there are a few remaining "compatibility functions", but I rewrote things which had native equivalents available.