Immunos:Free Secure Browser in beta stage

http://www.pentest.es/inmunos.php

 

Looks like a specialized Linux distro that utilizes PaX/Grsecurity. The PaX team are the people who "invented" ASLR and grsecurity is a closely connected project that provides a MAC system (with RBAC capabilities). Most Linux distros use neither of these tools because they require a lot of tweaking (and are overkill for most scenarios). Further, the Linux kernel has its own built in ASLR, stack smashing, RELRO and other protections (though not as strong as what PaX provides).

At any rate, ImmunOS project is not unique (in that there are other such hardened specialized distros out there), but it looks to be unique in the sense that it's made to run on top of a Windows VM host (which is technically possible to do with any other Linux distro, so that's really not unique either). At any rate, their methods and the technology used appear to be solid. It might be a nice tool for those who don't want to dual boot a full Linux distro.