Is it really full of new ideas? This looks like a fairly generic tagging system which seems to pop up on HN every few months. If you are interesting in tagging

Is it really full of new ideas? This looks like a fairly generic tagging system which seems to pop up on HN every few months. If you are interesting in tagging systems, I recommend you to look at Microsoft WinFS (part of Longhorn). This took idea of tags very deeply -- not only it had user-specified tags, but it would parse many existing file formats and automatically generate tags based on contents -- for example, if it saw a word doc and detected it is of "resume" type, it'd extract "Name, Educational Qualification, Experience" values from it. Sadly, there is no good single overview I know of. You can start from wikipedia (https://en.wikipedia.org/wiki/WinFS https://en.wikipedia.org/wiki/WinFS) and follow the links.