Linuxulator

Dr. Emmett Brown’s similar-sounding Flux Capacitor from the movie Back to the Future bridged the dimension of time, uniting past, present, and future for the McFlys. Similarly, the FreeBSD? Linuxulator project also bridges dimensions – in our case, these are Linux? and FreeBSD.

Linuxulator provides Linux ABI (application binary interface) compatibility so FreeBSD users can run many unmodified Linux applications and libraries without the need for virtualization or emulation. It provides the binaries with kernel interfaces identical to those provided by a Linux kernel, similar to the way 32-bit FreeBSD binaries run on top of 64-bit FreeBSD kernel. Since Linuxulator doesn’t rely on virtual machines or emulation, these apps often run as fast, and sometimes even faster, on FreeBSD as on Linux.

Linux binary compatibility, commonly referred to as Linuxulator, is a mechanism to run unmodified Linux binaries under FreeBSD. It allows FreeBSD to run unmodified Linux x86/x86_64 ELF binaries directly by translating Linux system calls to native FreeBSD equivalents — all within the kernel, with near-native performance. No virtualization or emulation required. It does not involve virtual machines or emulation; instead, it provides the binaries with kernel interfaces identical to those provided by a real Linux kernel. Technically it's similar to the way 32-bit FreeBSD binaries run on top of 64-bit FreeBSD kernel.

There are two main ways to use Linuxulator. First, documented in the FreeBSD Handbook, uses Linux applications provided as FreeBSD ports and packages, to be installed using pkg(8). Second, described at LinuxJails, provides a full Debian/Ubuntu userspace. The former is more user-friendly, but provides a limited number of available applications. The latter method is more involved, but is handy when doing development work. Both can be used at the same time.