Because moneta is not new at all, look at the commit dates :-) It only seems to have made it to HN because someone resurfaced it on Reddit recently.

I asked wycats about this and he said he plans to do some serious reworking on it soon.

It turns out the code used the Redis native expiration, but it wasn't compatible with Redis 2.x. So I fixed both problems. I sent a pull request. We'll see if it makes it into main.

http://github.com/subwindow/moneta

As a side note, the library is pretty simple at this point. The way the tests are set up is pretty excellent as well.

I don't think Moneta's Redis interface uses the ruby expiration code: http://github.com/wycats/moneta/commit/522be344cfeddb4a4dbf8...