cosmopolitan/README.md

Cosmopolitan

Cosmopolitan Libc makes C a build-once run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable.

Background

For an introduction to this project, please read the αcτµαlly pδrταblε εxεcµταblε blog post and cosmopolitan libc website. We also have API documentation.

Getting Started

If you're doing your development work on Linux or BSD then you need just five files to get started. Here's what you do on Linux:

wget https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-0.3.zip
unzip cosmopolitan-amalgamation-0.3.zip
printf 'main() { printf("hello world\\n"); }\n' >hello.c
gcc -g -Os -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \
  -fno-omit-frame-pointer -pg -mnop-mcount \
  -o hello.com.dbg hello.c -fuse-ld=bfd -Wl,-T,ape.lds \
  -include cosmopolitan.h crt.o ape.o cosmopolitan.a
objcopy -S -O binary hello.com.dbg hello.com

You now have a portable program. Please note that your APE binary will assimilate itself as a conventional resident of your platform after the first run, so it can be fast and efficient for subsequent executions.

./hello.com
bash -c './hello.com'  # zsh/fish workaround (we upstreamed a patch)

So if you intend to copy the binary to Windows or Mac then please do that before you run it, not after.

If you're developing on Windows or MacOS then you need to download an x86_64-pc-linux-gnu toolchain beforehand. See the Compiling on Windows tutorial. It's needed because the ELF object format is what makes universal binaries possible.

Cosmopolitan can also be compiled from source on any Linux distro.

wget https://justine.lol/cosmopolitan/cosmopolitan-0.3.tar.gz
tar xf cosmopolitan-0.3.tar.gz  # see releases page
cd cosmopolitan
make -j16
o//examples/hello.com
find o -name \*.com | xargs ls -rShal | less

Support Vector

Platform	Min Version	Circa
AMD	K8 Venus	2005
Intel	Core	2006
New Technology	Vista	2006
GNU/Systemd	2.6.18	2007
XNU's Not UNIX!	15.6	2018
FreeBSD	12	2018
OpenBSD	6.4	2018
NetBSD	9.1	2020