I believe all of those projects are based on single-core debugging. Restricting the trace to a single core is one way of introducing determinism in the process as a way of allowing replay later. Microsoft time travel debugging is a multi-core technology, which allows you to capture interactions between threads in multi-threaded processes.

Edit: Since I'm still "posting too fast", let me respond here to clarify. Both rr and undodbg support multiple threads, but do not record them simultaneously. They restrict execution to a single core. That's what I mean by recording interactions between threads. For instance, if you have shared memory between processes, that won't work with rr/undodb generally (although I know at least rr can work around this by recording both processes).

I'm not saying one is intrinsically better than the other since there are tradeoffs with both approaches. There is a high constant overhead for recording all cores, but it does have the advantage of scaling well to large numbers of cores.