I hope you are joking. Certainly there are fantastic people working on fantastic products that are GPL licensed. However, GPL is inappropriate for applications develpoed by vendors to be used by government. There are a multitude of open source licenses that would be more appropriate for this task (Apache, BSD, MIT, to name a few).

It seems you have some kind of axe to grind, and that's fine. But to claim that products such as Clang/LLVM, FreeBSD, Eclipse, FireFox, Perl, Tomcat, etc. somehow do not matter because they do not meet your requirement that they are not GNU (and thus aren't truly free because you can take their source code and do with it what you like, or that derrived works don't enforce a license, or they don't hace a wildebeast mascot... I don't actually know why you think non-GNU = trivial) sounds uninformed, glib, or narrow-minded, at least to my ears.

There are many other open-source licenses besides GPL.

Actually, jailbreaking is a *nix term, originating from code that is able to break out of a BSD jail. It basically refers to code that is able to access files that is otherwise protected (operating system, file protections, encryption, etc.). Rooting on the other hand refers to the ability to execute code with root privileges. Both refer to privileged escalation, jailbreak generally refers to file access whereas root generally refers to process access. Both of these terms have changes over time (e.g., Sony has a "rootkit" in some CDs that only affected MS Windows).

However, I think it is fair to say that in today's world, a jailbreak is something that is done intentionally by the owner of a device to gain access to features that are otherwise denied, whereas rooting is done by nefarious n'er-do-wells with evil intent. Oh yeah, and Sony.

You should check out They Might Be Giants' newest album "Here Comes Science" (a CD/DVD combo, available at Amazon for $13).

If your requirements are such that your "virtualized" machines can all run FreeBSD, then there is no reason not to leverage the jail system. It is robust, fast, and very secure. The current version of FreeBSD has added features to jail making it even more attractive (as well as simple to use and maintain). And since you are running FreeBSD, you have access to CARP, providing load-balancing and failover, as well as ZFS, the bee's knees of file systems.

Compare this with a vm solution (pick your favorite), where not only do you have to maintain multiple OS instances (one per VM) but also have to maintain the vm structure itself. I am not claiming that either of these tasks are that onerous, rather that they are tasks that are not required in the jail solution. And what do you get in return for these extra steps that you do not get with a jail? By all means, if there is something that a vm solution provides that cannot be done in a jail, then go for it; but dismissing jails out-of-hand doesn't serve anybody.

If all of your virtual machines can fun FreeBSD, the question really becomes, "why introduce levels of complexity when they are not required, impact performance, add security risks, and make the overall system more difficult to maintain?" The problem with a FreeBSD jail/carp/zfs solution isn't that it is inferior in any way; rather that, looking at OS popularity, FreeBSD is a distant third (forth really, but virtualizing Mac OS breaks licenses (and I don't really know where Solaris fits)) so FreeBSD is frequently not an option as it may not meet the requirements of the application. This may be mitigated with the Linux compatibility package and/or Wine; but you may want to run your Linux applications on a Linux machine (virual or otherwise), and likewise with your Windows apps.