PostgREST is a standalone web server that turns your PostgreSQL database directly into a RESTful API. The structural constraints and permissions in the database determine the API endpoints and operations.
The DBacesslayer aka DBSlayer aka Släyer is a lightweight database abstraction layer suitable for high-load websites where you need the scalable advantages of connection pooling. Written in C for speed, DBSlayer talks to clients via JSON over HTTP
Representational state transfer (REST) was introduced in early 2000 by Roy Fielding's doctoral dissertation. However, in the Java community, it was not standardized until JSR 311(JAX-RS) was finalized in 2008. The first release of its reference implementation is even later. In this article, I introduce Jersey, which is the reference implementation of JSR 311, by describing its essential APIs and annotations. I'll also show you how you can smoothly transfer from servlet-style services to RESTful services by integrating Jersey into Apache Tomcat.
The Django REST interface makes it easy to offer private and public APIs for existing Django models. New generic views simplify data retrieval and modification in a resource-centric architecture and provide model data in formats such as XML, JSON and YAML with very little custom code.
R. Krummenacher, B. Norton, und A. Marte. Future Internet -- FIS 2010: Third Future Internet Symposium, Berlin, Germany, Volume 6369 von Lecture Notes in Computer Science, Springer, Berlin, (2010)