why I should use your module?

[timaschew]

Jade can compile templates for client side as well: https://github.com/visionmedia/jade#browser-support

[IanIan123]

This module uses the same Jade API under the covers.

[timaschew]

but why I should use this one instead of the origin jade?

[rhou-sdcc]

ClientJade added inline runtime.js code inside their generated files so that you can use them directly, plus with 2 ways of rendering data, .render and .template. Check the generated file and you can see the differences.