FECK is/was a dump of my code base at the time. It's not supported a great deal and isn't updated regularly. There's no official build it's intended as a bunch of example code to hack about with. However, it covers a wide range of areas including 3D rendering.

Slick is regular library for 2D gaming. It contains alot of the 2D stuff from FECK updated and with a simplified interface. It's intended to be used a library and gets regular updates, bug fixes and feature adds. It is however totally focused on 2D games, nothing else.

Hope this helps,

Kev