Yes. One approach is to use a language that allows both GC and manually managed memory, perhaps a small subset of the full language proper. You then write the

Yes. One approach is to use a language that allows both GC and manually managed memory, perhaps a small subset of the full language proper. You then write the garbage collector itself and other runtime bits in that language. Another approach is to reduce the GC runtime to as small a blob as possible, and write it in C/assembly. The old LISP machines used both techniques -- there was an assembly language of sorts, that mapped closely to the high-level language, in which the most basic layer of the system like the GC was written.