Yeah, the pages linked from those HN links don't seem to exist, but you can still download it:

https://github.com/lucaspiller/shortly

I was always quite fascinated by the concept, but I suspect liability and lack of control over the content is a fatal issue and why nothing much seemed to come from it.

If someone makes a 'bad' page, which is inevitable, the domain with the hashify/shortly code would be held responsible and the only way the site owner could 'remove' the content would be to stop the service.