The caveat there is you can write up a fairly simple nosql database in an afternoon. What I like about the other projects is that the barrier to even a minimal

The caveat there is you can write up a fairly simple nosql database in an afternoon. What I like about the other projects is that the barrier to even a minimal thing is a bit higher. I think that leads to more opportunity to work your creative muscles. Though if you add some constraints like it must have jdbc compatability then that becomes interesting.