Here is my problem with all these (pseudo)small request handling frameworks.... They seriously tightly couple your code with a relatively unproven library. Not mention most of them use a fair amount of singletons and static initialization.<p>Most web applications require an enormous amount of controllers and even micro services typically require a fair amount of routing and request&#x2F;response handling. Not to mention security, the asynchronous model, future HTTP2 support. I&#x27;m not exactly comfortable using something like this for a moderately size project nor even small project.<p>I have also seen like 6 or so micro frameworks in the last couple of months. Just two of them offhand I remember:<p>* Rapidoid - seems to be smaller.<p>* Jooby - not smaller but seems more mature.<p>Most of them just build off of Netty (at least some project realize they shouldn&#x27;t be redoing the low level).<p>I honestly think there should be a slimmed down modern servlet&#x2F;jaxrs api spec that should be designed in a similar manner to how the reactive-streams api was designed (ie make a github repo, file issues, take pull requests and get the damn interfaces right).<p>We also have the same problem going on with Singles aka Promises aka Deferreds aka Future with callbacks (dozens and dozens of implementations exist). Right now I&#x27;m using rx.Single but just about every framework has its own (reactor, Play, Akka, JDeferred, etc etc).<p>At least streams aka Flow will be in Java 9.