Pyston roadmap

We’ve spent some time recently thinking about the future of Pyston, our faster implementation of Python, and wanted to share what’s on our mind. For updates please check out our wiki.


Our primary goal at this point is to get more people using Pyston, and our initial approach to that will be removing some of the reasons that make it difficult to use Pyston. We are currently 30% faster on our benchmarks and 60% faster on commonly-used benchmarks, and while being even faster would entice more people to use Pyston, we believe we will have a bigger impact by reducing obstacles than by working on performance.

The most common issue that our users report is not being able to install the packages they want. This happens because some packages are difficult to compile; CPython users will typically download pre-compiled versions, but there aren’t pre-compiled packages for Pyston yet. So our current focus is building these packages for our users and providing them in a way that’s easy to install.

To do that we’ve decided to provide the packages through conda. There are a few benefits of this: first it lets us provide the packages ourselves instead of waiting for package maintainers to produce Pyston builds, second it makes it easier for users to get Pyston in the first place, and third it will hopefully make us more portable in the process and work on more Linux distros.

After that we have many things we’d like to do, with the exact order to be determined:

  • Set up a CI/CD system
  • Add support for 64-bit ARM
  • Continued performance improvements

And even longer term:

  • Add Mac and Windows support
  • Integrate with Numba
  • Improve multithreading
  • Explore “opt-in” features that allow us to break semantics
  • Continued performance improvements

Target Python versions

We’ve decided that we only have the resources to target a single version of Python at a time. We would love to be able to provide a version of Pyston regardless of the version of Python you want, but that’s not feasible given our small team.

We currently target Python 3.8.12, and plan to retarget to Python 3.10 some time in early 2022. We intend to backport parts of the “Faster CPython” effort going on in 3.11 depending on the level of compatibility.

We are open to backporting semantic changes made in later versions of Python if we think this means the Python community has decided a certain feature is implementation-dependent. We anticipate that these are largely performance improvements that have small technical semantic differences; we do this on a case-by-case basis, and make a note of it on our wiki.

Supported Pyston versions

While we will try to help with any version of Pyston you are running, because our project moves quickly we won’t be backporting fixes to older versions of Pyston.

If you have any questions/thoughts/suggestions please feel free to join our Discord or file an issue on our GitHub!