MBSL (MicroBlaze Simple Linux) is a set of Makefile scripts to create an image of a Linux-based OS for the Xilinx MicroBlaze (FPGA) soft processor. It provides very simple package management that allows you to customize the resulted image. The purpose is to just type 'make build install' and get the configured image.
rgbproc-repository is intended for use with Xilinx EDK tools. It consists of many units written in VHDL that can be used to build a design for image/video processing. The backbone is the data bus (called simply RGB) that is used to pass data (typically) from VGA input to VGA/DVI output.