In 2001, I wrote a tag balancer (for HTML input, it also did some rudimentary XSS filtering) in PHP and then translated it to Cold Fusion (I was applying for a

In 2001, I wrote a tag balancer (for HTML input, it also did some rudimentary XSS filtering) in PHP and then translated it to Cold Fusion (I was applying for a CF job and figured it might be useful to actually learn it). I believe that both variations are still running, the CF version on Metafilter, and the PHP version was used in B2, which became WordPress. A few years ago, I was asked by the WP team to relicense the code from GPLv2 to GPLv2+ and sure enough, it lives on with relatively few modifications in WordPress: https://github.com/WordPress/WordPress/blob/b1804afeaf07eb97b0384281efcee1b3ca4ce1f8/wp-includes/formatting.php#L1772 https://github.com/WordPress/WordPress/blob/b1804afeaf07eb97... Perhaps most notable, is that I wrote it w/o having taken a compilers class or having much (any) understanding of stack-based parsing, but it still lives on, so I guess it was good enough to get the job done.