I'm thinking of playing around with a lesser-used, more obscure open source operating system in the near future to see if I can get all of my work done with it for a couple of weeks. Open to suggestions as to which one to use.

Edit: I should have made this clear. It will _not_ be a Linux distro. More obscure than a Linux distro I've reviewed before.

@devSJR I know ReactOS won't work. Tried it recently and it crashed non-stop every few minutes. And I know Void will work perfectly because I review it about once a year.

Haiku and OI are good possibilities.

@distrowatch I'd say not OpenIndiana, but #Tribblix. Peter Tribble did a great job with Illumos kernel. I used it for some time several years ago and was surprised how easy and straightforward it turned out to be.
@chesheer I just finished writing a review of Tribblix, it''ll be out on Monday.
@distrowatch That's great! Looking forward to it.
I remember that when I first tried Tribblix it didn't even have Distrowatch page.
DistroWatch.com: Tribblix

News and feature lists of Linux and BSD distributions.

@distrowatch @chesheer
DragonflyBSD?
I've never tried yet, and based on FreeBSD, but forked early enough (before 5.0, as the developers didn't like upcoming SMP implementations [ULE, KSE] of FreeBSD5.0).
And Hammer FS looks interesting, if it already works well.