From the readme:
This is a simple port of FreeRTOS to LPC2119 (specifically the Futurlec/ETTArm-Stamp). Al Williams http://www.awce.com
You should get the FreeRTOSV5.2.0 distribution and unpack this in theDemo directory so you wind up with.../FreeRTOSV5.2.0/Demo/ARM7_LPC2119_GCC.
The configuration items are near the top of the Makefile and in FreeRTOSConfig.h
You can type make to build or "make program" to build and run the downloader.
You can define USE_NEWLIB in the makefile as 1 to use newlib (assumes you have it and newlib-lpc). However, note that newlib-lpc timers interfere with the rtos scheduling!
The 2119 doesn't have enough resources to do all the tests so you can pick the ones you want in main.c. In addition, you can't run the 8 floating point tasks so if you want to enable floating point task you'll have to replace ../Common/Minimal/flop.c with the file in this directory.