Besides the GRS library described in the previous section, VISTA includes many other high-level libraries which fulfill specific needs in the framework. Some of them implement semantic constraints as already discussed in Section 6.2 like the GAS (Geometry Attribute Support) library, others provide framework services like the G2S (Geometry 2-dimensional Support) and the MAT (Material Support) libraries, and yet others provide a distinct view of PIF data for certain applications like the CLS (C List Support) library. A concise overview of those libraries shall be presented in the next few sections without going into further detail.