Another path-based MAC system like AppArmor; I've probably mentioned in before. It seems to have gotten better in recent versions. Advantages vs. AppArmor: - Has a system-wide learning mode a la GrSecurity, which AppArmor lacks. - Seems to control access to more stuff, e.g. environment variables (as of kernel 3.7.x). - Almost all the major distros IIRC have support for it; Arch, Debian, and Ubuntu also have the userspace tools. - You can specify different policies for the same program, under different conditions (e.g. depending on the parent process). Disadvantages: - Policy editor is harder to use than AppArmor's tools as of right now, and the interface is a little confusing (especially the keybindings). - There are some gotchas for newbies in the default behavior. For instance, if you launch Firefox and set its policy to learning mode, per default the generated policy will only apply to Firefox if launched by the same parent process, which is not what most people want! - Policy rules are a bit less obvious than AppArmor's, and more of a pain to edit (policy editor strangeness again). - In the absence of manually added rules, globbing seems to be done automatically after a certain number of similar rules are applied. This is probably friendlier for Linux novices, but not so great if you want fine grained control. My take: Tomoyo is probably a reasonable alternative to AppArmor, and good to have on systems where the latter is not available. Its behavior is actually a little like Geswall or Malware Defender on Windows, with learning mode and all, so people migrating from Windows might find it simpler to use. OTOH it makes fine-grained control a bit more cumbersome than AppArmor; and the behavior of the policy editor (in lieu of a standard text editor) can be a little painful. Still, it's nice to see the widespread adoption of Tomoyo in distros' stock kernels. At the moment, I believe Slackware is the only major distribution that ships without a MAC system compiled into its kernel; the others all have one or more of Tomoyo, AppArmor, or SELinux.