[plorkyeran]

Compacting garbage collectors don't have fragmentation issues, but of course Go doesn't have one. A GC isn't even strictly a prerequisite for compaction. Manually combining memory allocations to reduce allocator overhead and fragmentation is a lot of work, but not unheard of.

[ridiculous_fish]

The Classic Mac OS API (the "toolbox") had a compacting manual memory management scheme. Instead of raw pointers like what malloc might return, you worked with double-pointers called Handles (different from Win32 Handles), which indirected through a global Handle table. System calls may compact or rearrange the blocks of memory referenced by Handles. If you wanted to dereference the Handle across a system call, you had to HLock it to keep it from being moved, similar to object pinning in C#.

In modern OSes, virtual memory plays an analogous role. We still have a double indirection, but it goes through the TLB and page table.

[gillianseed]

>Compacting garbage collectors don't have fragmentation issues

At the expensive cost of moving memory blocks around in the managed heap, there is no silver bullet.