The ATERM Library is a well-designed and well-known library in the term rewriting community. In this paper, we discuss the current garbage collector provided with the library and stress the fact that some peculiarities of this functional library could be taken advantage of by the memory management system. We explain how we designed and implemented GC 2 , a new mark-and-sweep generational garbage collector for the ATERM Library that builds upon these peculiarities. Experimental results on various programs validate our approach, and show that the performance of our new algorithm is very good.