We are proud to announce Pyston v2.2, the latest version of our faster implementation of the Python programming language. This version is significantly faster than previous ones, and importantly is now open source.

We also merged in many changes from CPython and are now based on CPython 3.8.8.

Performance

Pyston v2.2 is 30% faster than stock Python on our web server benchmarks. This is a significant improvement over our previous performance, and if we were feeling cheeky, we would advertise it as “50% more speedup.”

The foundational technology powering Pyston v2.2 is the same as that found in earlier versions, but we have tuned and optimized more areas and found additional speedups, particularly in our JIT and attribute cache mechanisms.

One noteworthy change is that we decided to remove many of the rarely-used debugging features that Python supports because they are expensive even when not needed. Doing so collectively resulted in a 2% speedup, which was remarkable to us: of all the computers in the world running Python, 2% of them are executing debugging checks. We’ve disabled those checks and are positioning ourselves as an “optimized build” similar to binaries without debugging information. Those who still want debugging features can use the “debug build” of stock Python because they are interchangeable. For a full list of the features we removed in Pyston v2.2, please see our wiki.

Open source

As we’ve continued talking to potential customers we now feel convinced that Pyston can thrive on an open-source business model, primarily by starting with support services. This means that we’ve open sourced Pyston v2.2, which you can find at our GitHub here.

We’ve archived our old repository to reduce confusion, but you can still find that here.

We are looking into which of our newest changes can be upstreamed to CPython. Throughout this process, we welcome your contributions. Help with getting Pyston packaged for additional platforms would be especially useful.

Moving forward

We continue to try and make Pyston as compelling and easy to use as possible. Working Pyston into your projects should be as easy as replacing “python” with “pyston.” If that’s not the case, we’d love to hear about it on our GitHub issues tracker or on our Discord channel. We hope you’ll give Pyston a try and see that it really is the easiest way to speed up your Python code.