This is a maintenance fork
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Justine Tunney c91b3c5006 Initial import 3 years ago
ape Initial import 3 years ago
build Initial import 3 years ago
dsp Initial import 3 years ago
examples Initial import 3 years ago
libc Initial import 3 years ago
net Initial import 3 years ago
test Initial import 3 years ago
third_party Initial import 3 years ago
tool Initial import 3 years ago
usr/share/zoneinfo Initial import 3 years ago
.clang-format Initial import 3 years ago
.gitignore Initial import 3 years ago
Makefile Initial import 3 years ago
NOTICE Initial import 3 years ago Initial import 3 years ago


Cosmopolitan builds run natively on most platforms without dependencies, because it implements the subset of the C library, compiler runtimes and system call interfaces that've achieved near universal consensus amongst all major platforms, e.g. Linux/BSD/XNU/NT. Containerization is achieved by having binaries also be ZIP files. Modern static stock GNU toolchains are provided in a hermetic mono repo for maximum historical determinism.

Here's how you can get started by printing cat videos inside a terminal:

make -j8 o//tool/viz/
o//tool/viz/ cats.mpg
unzip -vl o//tool/viz/

Cosmopolitan provides a native development environment similar to those currently being offered by RedHat, Google, Apple, Microsoft, etc. We're different in two ways: (1) we're not a platform therefore we don't have any commercial interest in making our tooling work better on one rather than another; and (2) we're only focused on catering towards interfaces all platforms agree upon. Goal is software that stands the test of time without the costs and restrictions cross-platform distribution entails. That makes Cosmopolitan an excellent fit for writing small CLI programs that do things like heavyweight numerical computations as a subprocess.


Cosmopolitan is Free Software licensed under the GPLv2. The build config will embed all linked sources inside your binaries so the compliance is easy while facilitating trust and transparency similar to JavaScript. You can audit your source filesystem using ZIP GUIs e.g. WIN10, InfoZip.

Commercial Support

If you want to be able to distribute binaries in binary form only, then please send $1,000 to on PayPal for a license lasting 1 year. Please be sure to provide your contact information, and details on whether or not the license is for an individual or a corporation. If you want your license to last 5 years, send $10,000 to the author above who is Justine Tunney This README will be updated, if pricing and other details should change. Reach out for more details.


We'd love to accept your patches! Before we can take them, we have to jump through one legal hurdle. Please write an email to Justine Tunney saying you agree to give her copyright ownership to any changes you contribute to Cosmopolitan. We need to do that in order to dual license Cosmopolitan. Otherwise we can't tax corporations that don't want to share their code with the community.