FeatureServer is a GeoLatte project designed to serve geometric features through a REST-based API. Goals of featureserver are:

Minimalistic configuration: typically, all you need to do is specify the database/schema/tables you wish to serve and you're done. Although FeatureServer uses Hibernate behind the scenes, there is no need to write mapping files to use FeatureServer.
Standard compliance: FeatureServer supports standardized input and output formats. For querying, CQL is used. For output, both (Geo)JSON and CSV are currently supported. Future formats will be added in the near future.
Convenient API: Interaction with FeatureServer is done through a simple REST-based api. Just connect your browser or program to the right HTTP port, and start querying.

Useful links you might wish to visit:

REST API for Feature Server: http://www.geolatte.org/confluence/display/fserv/Rest+API