The why's

Why Hope?

For a while I have continued to develop the json-rules project and it is battle-tested in production over billions and billions of evaluations. However, as the evaluation criterion grow bigger and deeper, there is a need for brevity and more performance.

Hope is a step towards that direction.

Why json only and why jackson?

I believe at this point of time, json is the single most lucrative serialization standard to invest in. Yes, it has it's limitations, but it's very simple to work with and has a rich set of libraries in many languages.

As for jackson, a lot of server side projects use jackson to work with JSON. I believe useful projects solve for real life problems and all server side projects I work with use Jackson. Could it be made to use something else like Gson.. yes probably, but I'd rather cross the bridge when I get there.