These are the compiler tools installed as part of CCS. When you build a project in CCS, these tools (compiler, linker etc) are invoked. The documents that specifically describe these tools are ARM Compiler Users Guide and ARM Assembly Language Tools Users Guide.
Also this wiki article should be of help in understanding the CCS build process and general flow and where the compiler tools fit in in the overall CCS build flow: http://processors.wiki.ti.com/index.php/Projects_and_Build_Handbook_for_CCS