check out my shitty text board implementation

in 75 lines of php

[url=http://54.245.123.189/190chan/]http://54.245.123.189/190chan/[/url]

it has no sql or html injection protection

SOURCE
[url=http://54.245.123.189/190chan/index.phps]
http://54.245.123.189/190chan/index.phps
[/url]

HOSTED THANKS TO AMAZON E CEE TWO

http://wiki.whatwg.org/wiki/HTML_vs._XHTML
HTML does not have a well-formedness constraint, no errors are fatal. Graceful error handling and recovery procedures are thoroughly defined.
This is why HTML is so much better than strict XHTML. With XHTML, one missing or misplaced tag and the whole page won't render. With HTML, you can forget start or end tags, partially overlap your formatting tags, use tags and attributes the browser doesn't understand, throw in unmatched angle brackets, and it'll still parse. In some of these cases it'll still know what you mean. Few of the tricks in OP's textboard would be possible with a strict language like XHTML.

>>54
XHTML is easy to parse. Poorly formed markup is a real pain to deal with. If you're writing HTML, you should be doing it correctly in any case.