A new article is available on os4.hyperion-entertainment.biz outlining the new and improved memory system on AmigaOS4.0. It describes the method of "slab allocators" and "object caching" that greatly reduce external memory fragmentation while keeping internal fragmentation to a guaranteed minimum and typically provides a constant-time memory allocation.
Read all about it on <a href=http://os4.hyperion-entertainment.biz target=_blank>os4.hyperion-entertainment.biz</a>