MirageOS Blog

I read three books at a time, and only pick up/start/buy a new one once I finish one. Helps acquiring a large back log of unread literature around the apartment. :)

* Labyrinths - Jorge Louis Borges [0]
I believe HN was the reason I picked this up, if I remember correctly. It's a collection of short stories, each of which can be finished in a night, which is satisfying. I really dig his writing style and fantastical nature of the stories. I've done a bit of philosophical reading but a lot of the references he makes go over my head, leaving me to do a bit of research after each story.

* The Design of Everyday Things - Don Norman [1]
Picked this up after finishing Debbie Millman's How to Think Like a Great Graphic Designer [2] (Misleading title, I would 100% recommend this book to anyone). I'm not sure what I expected, but so far this hasn't been satisfying. The first couple of chapters have been laying out a framework and defining terms. Considering swapping this out for Jon Kolko's Well Designed - How to Use Empathy To Create Products People Love [3], which seemed much more actionable after picking it up at Barnes and Noble.

* Real World OCaml - Yaron Minsky, Anil Madhavapeddy, Jason Hickey [4]

Second time picking this up, originally read up to chapter on Functors over the summer. I started over this time and I'm about finished with the first section, "Language Concepts", now. It's worth noting that the entire text is available online for free on the book's…

If you find this interesting you may want to read about this more current research:
http://www.openmirage.org/

To quote from the vision paper http://anil.recoil.org/papers/2010-bcs-visions.pdf

Mirage is written in the spirit of vertical operating
systems such as Nemesis [17] or Exokernel [10], but
differs in certain aspects: (i) apart from a small runtime,
the operating system and support code (e.g., threading)
is entirely written in OCaml; and (ii) is statically
specialised at compile-time by assembling only required
components (e.g., a read-only file system which fits
into memory will be directly linked in as an immutable
data structure). These features mean that it provides
a stronger basis for the practical application of formal
methods such as model checking; and the removal of
redundant safety system checks greatly improves the
energy efficiency of the system.

I have started playing with Rust and have used OCaml on and off, but recently really diving hard into it building a REST-based application from top to bottom in OCaml, including all the infrastructure bits. We are slowly making our stuff open source as it becomes useable: https://github.com/afiniate

In short, OCaml is a mature language that has been used for decades in commercial applications. I feel OCaml is the next progression for the people that got excited about distributed systems via the Erlang path and want more of the safety and reasoning that comes from a strongly/statically-typed language like OCaml. Rust may or may not take off, but I am confident OCaml will remain viable for the foreseeable future, and probably gain slow, but steady popularity as engineers see all the cool things you can do like MirageOS: http://openmirage.org/

They're of course not a desktop option at all, but there's also some very interesting work happening with unikernels, which are really only recently a viable option now that Xen can present a unified hardware layer, instead of the endless treadmill of specific drivers. I've been getting into OpenMirage [1] quite a bit recently, largely due to the energy of the team [2], but also looked a bit at HalVM [3]. I definitely recommend [2] for anyone interested in plausible ideas of what the one of the next generations of VM/apps might look like.

[1] http://www.openmirage.org/
[2] https://www.youtube.com/watch?v=UjonFD-2ATo or http://www.se-radio.net/2014/05/episode-204-anil-madhavapeddy-on-the-mirage-cloud-operating-system-and-the-ocaml-language/ (audio only)
[3] https://github.com/GaloisInc/HaLVM

No wonder OCaml compiled to native is faster than other MLs and Python. I rem stumbling on benchmarks elsewhere, where compiled OCaml rivaled CPP in terms of performance on certain tests.

In my experience with OCaml, I have found the syntax a bit too unfavourable like the author did, but the resulting code was very fast. With concurrency sorted out, I wonder if it could take on Rust, Nim, and Go as far as systems-programming is concerned (esp since Go has the weight of Google behind it).

It also helps that the language designers have written a large tutorial on systems programming: https://ocaml.github.io/ocamlunix/

Then there's this epic Mirage OS built with Cloud Computing in mind by Anil and his team of OCaml zealots: http://openmirage.org/

Since there has been a resurgence of interest in OCaml on HN, some may be curious to see how a production quality Btree implementation looks like in OCaml. Algebraic data types, make it particularly convenient for these sorts of things. For comparison one may contrast it with an implementation in a language that does not have algebraic types, C++ for example. So glad Rust chose to have them.

Here is a Btree implementation from the mirage project [1]
https://github.com/cgreenhalgh/ocaml-btree/blob/master/lib/btree.ml

EDIT: removed link to binary tree after kerneis pointed it out.

[1] http://www.openmirage.org/