A simple page I made some time ago.
Divides Polish words into syllables, and displays a realtime tabular preview of a poem's structure. For example, Adam Mickiewicz's famous lines can be clearly seen to follow the famous traditional trzynastozgłoskowiec structure.
Here: aleshkev.github.io/vyershark.
The algorithm is pretty naive, inspired partially by the rules Polish Wiktionary uses to convert words to IPA automatically. It turns out, the vast majority of traditional words have simple letter-vowel correspondence. The task is made even simpler by the decision not to divide words into syllables, but to count them.
I'm like how the look of the page turned out, the minimal amount of CSS made it look very minimal and clean.