> Modern CPUs also don't have hardware GC support. Intel i432 was the last attempt at it.
Intel i432 was far from the last attempt. Besides all of the Lisp HW developed after it, Azul made CPUs in the 2000s with hardware support for GC. Acceleration of concurrent copying collection requires a surprisingly low amount of CPU support.
I had my history reversed regarding i432 vs Lisp HW.
You are right I also forgot about Azul, but eventually they dropped it, because it wasn't worthwhile anymore, just like it happened with all other specialized hardware implementations.
Azul (and AFAIK most lisp machines) does not do garbage collection in hardware. In these contexts the "GC HW" involves hardware acceleration of read/write barriers required by concurrent and incremental GCs (which otherwise requires the compiler/JIT to inline implementation of barriers into user code). The reason why Azul can now use stock amd64 CPUs is that they found that you can abuse the MMU to provide exactly this kind of HW accelerated barriers.
Modern CPUs also don't have hardware GC support. Intel i432 was the last attempt at it.
Interaction with DOM can be achieved with a few imported functions.