You shouldn't overlook Orbeon Forms, it has history going back to 2007 (it seems quite mature).
I believe it can just be used like a robust black box to do both CRUD and HTTP web front ends.
There is an open source (LGPL) Community Edition, but the services & actions feature you need for this is only available in the Professional Edition. This being said, if you just need this for your own local testing, you can get a trial license (automatic process, valid 3 months, no limit on number of licenses you get), and have fun with it.
Bias: I'm one of the Orbeon Forms developers ;). ‑Alex