Cosmopolitan v3.5: The Cross-Platform Solution You’ve Been Waiting For

In the world of software development, one of the most daunting tasks is creating applications that can seamlessly run across different operating systems and hardware architectures. Enter Cosmopolitan v3.5, a tool that promises to make this easier than ever before. Developed with the goal of portability, Cosmopolitan allows developers to build a single binary that works on multiple platforms, without sacrificing performance or compatibility. This tool is not just another run-of-the-mill solution; it’s a game-changer that streamlines many aspects of the development process.

One of the first questions that comes to mind is the extent of its cross-platform capabilities. The short answer is, Cosmopolitan supports both AMD64 and ARM64 architectures. The beauty of this lies in its ability to create fat binaries—executables that contain multiple formats for different architectures. Unlike the dual-architecture binaries that can bloat software size significantly, Cosmopolitan keeps this increase minimal, usually between 30-50%. This allows these applications to remain lightweight and agile, all while maintaining robust cross-platform compatibility.

The list of supported platforms is extensive, ranging from various Unix-like systems to Windows. For those questioning its compatibility, a simple perusal of their detailed documentation available on [Justine’s blog](https://justine.lol/cosmo3/) and [Cosmopolitan’s GitHub repository](https://github.com/jart/cosmopolitan/blob/master/tool/cosmocc/README.md) offers a wealth of information. You’ll find that this tool isn’t just limited to desktop environments; it’s equally viable on server setups, and potentially even embedded systems.

A particularly fascinating aspect of Cosmopolitan is its functionality as a single binary that operates in a cross-OS, cross-arch manner. You can download an executable directly from [Cosmo’s bin directory](https://cosmo.zip/pub/cosmos/bin/) and verify its effectiveness across various setups. For an illustration, check out these commands executed on macOS with an M1 chip, and FreeBSD with an amd64 chip:

  % curl -O https://cosmo.zip/pub/cosmos/bin/basename
  % chmod +x basename

On macOS with an M1:

  % arch
  arm64
  % sha256sum basename
  2e4cf8378b679dd0c2cdcc043bb1f21eaf464d3c3b636ed101fbc5e3230eb5fb  basename
  % file ./basename
  ./basename: DOS/MBR boot sector; partition 1 : ID=0x7f, active, start-CHS (0x0,0,1), end-CHS (0x3ff,255,63), startsector 0, 4294967295 sectors
  % ./basename /dev/null.txt
  null.txt

On FreeBSD with amd64:

  % uname -sm
  FreeBSD amd64
  % sha256sum basename
  2e4cf8378b679dd0c2cdcc043bb1f21eaf464d3c3b636ed101fbc5e3230eb5fb  basename
  % file basename
  basename: DOS/MBR boot sector; partition 1 : ID=0x7f, active, start-CHS (0x0,0,1), end-CHS (0x3ff,255,63), startsector 0, 4294967295 sectors
  % ./basename /dev/null.pdf
  null.pdf

The sheer versatility of Cosmopolitan should not be overlooked. The project goes beyond just being a compiler; it provides a development environment that fragments usually suffered when developing software for multiple platforms. Cross-compiling often requires dealing with different compilers, linkers, and build systems. Cosmopolitan sidesteps these complications by configuring stock GCC and Clang to output binaries in a format approved by POSIX standards, ensuring that your application has the same quirks everywhere. This stable build environment negates the digital gymnastics typically involved in cross-platform development.

Another attractive feature is Cosmopolitan’s lean design, which means that despite the robustness it offers, the resulting executables are efficient and not overly bloated. For instance, the development of vectorized string libraries like strlen() hailed Cosmopolitan as being twice as fast as Musl libc in many command-line interface programs. Moreover, its malloc() function is meticulously optimized, creating a dynamic memory allocation environment that’s both rapid and reliable. Leveraging Mike Burrows’ synchronization primitives further elevates its prowess in concurrent programming, making it a compelling choice for not just CLI but also multi-threaded applications.

This series of innovations in efficiency, compatibility, and simplicity has not gone unnoticed. Mozilla’s LlamaFile, a rendition of the famous llama.cpp codebase used for running local LLMs, has demonstrated a fourfold performance gain by adopting Cosmopolitan. For developers, this signifies a potent melding of productivity and performance that transforms how applications are built, packaged, and distributed. Cosmopolitan also supports robust tools like Redbean—a web server with Lua scripting capabilities, suitable for embedding dynamic web applications. This makes the framework versatile enough to cater to a broad spectrum of software needs, from high-performance computing to web hosting.

In summary, Cosmopolitan v3.5 is a beacon of progress in an industry constantly grappling with fragmentation across platforms and architectures. By offering an integrated development environment capable of generating efficient, portable executables, it stands to streamline development workflows significantly. Its commitment to maintaining compatibility while pushing the boundaries of performance is commendable. With tools like Cosmopolitan, the elusive dream of building truly portable software is not only achievable but also practical and efficient.