Justine Tunney

Actually Portable Executable


I designed the Actually Portable Executable format which makes it possible to build native local-first programs as a single file that’ll run on the six major desktop / server operating systems, in addition to booting from BIOS / EFI as its own operating system too. The APE format is used by the Redbean web server, and has been ported to several languages such as Python, Perl, and OCaml.

Right now I’m focusing on helping these portable binaries reach a broader audience, that includes Apple M1, Raspberry Pi, Haiku, and other platforms, while staying true to the single file vision. I’m doing that by building an embeddable JITing virtual machine called Blinkenlights that’s as fast as Qemu while having a 10x smaller footprint. I’m patching kernels like Linux to have better native support for APE, and cross-compiling Cosmopolitan Libc to native ARM. Blink is also going to help bring APE binaries to the web, by compiling it to WASM. This will help us bring Linux software to the browser, with fast downloads since Blink doesn’t require that we emulate the Linux kernel too.


I’m excited to collaborate on any low-level bit fiddling project, particularly operating systems, system calls, emulators, libraries, and compilers.

I’m especially interested in collaborating with anyone who has ideas that will help APE reach more operating systems and hardware architectures. For example, building a JITing virtual machine for ARM has been very rewarding, since it not only helps us better serve Apple users, but it opens the door to also supporting more freedom-focused underdog hardware like RISC-V and OpenPOWER.

Headshot of Justine Tunney


Justine is an activist who started as a cyber security hacker and used that experience to improve the security of open source software. She is the creator of Redbean, an open source web server that allows you to build local web apps in a single zip executable.

Mission: Extend the reach of universal binary files from x86 chips to work on ARM chips.

Interests: Just like when I helped organize a community in Zuccotti Park where anyone could show up, camp without asking permission, and reinvent a better world to match their own visions, I also believe in helping software developers do the same. My projects like Actually Portable Executable overcome artificial restrictions that create toil for developers, and they empower open source devs to reach a broader audience. I believe in elevating the quality of software through world class engineering, and most importantly, making that accessible to every member of our society.


Want to collaborate with MIECO?

We are constantly looking for new ways to collaborate with individuals and organizations who share our passion for building a healthier internet. Whether you want to be a guest speaker to our cohorts, a potential partner who can provide additional resources, or someone that just wants to support the MIECO program in some shape or form, we’re all ears!

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