UENISHI Kota

What operating system are you using? Most Linux distributions has OpenMPI available from package manager. For example, in Ubuntu it's quite easy like `apt-get install openmpi-bin` and `pip install mpi4py`....

Some of us are using [mpienv](https://github.com/keisukefukuda/mpienv). Hope this helps.

It would be great if ndarray is supported as primitive type, as it's [binary protocol](https://docs.python.org/3/c-api/buffer.html#numpy-style-shape-and-strides) is important in Python for performance, being contiguous and having zero copy. By the way,...

BTW, I wasn't able to see the change in this pull request. I would prefer being an extension type rather than using unused identifier like `0xc1`. It still should be...

Fmmm. Do you know how easy is it to register? Looks like there's [an application page](http://www.iana.org/form/media-types) and vendor/personal formats are rather easier to register. Standard formats requires being standardised, that's...

-1 on putting any tags and versions to the spec - although I believe that depends on each library's maintainer. If all maintainers, including @frsyuki, that may happen. Although, I...

Also, it is guaranteed that objects serialised with old spec can be deserialised with new spec libraries (I dare not use the word 'compatible'), as the new spec was carefully...

I'm not sure why we need this. Where to publish? What if spec.md has been updated? I think Github does enough pretty printing. Managing multiple duplicated documents are extremely hard.

I don't think this should be done in binary representation level, but with on top of MessagePack object level.

+1 to @lyrachord, chunking your object stream to fixed length arrays seems fair enough, plus, maybe finishing the stream with null or stuff like that. At least it's not the...