The main implementation language for WingCash is Python. See it on GitHub. We chose Python for its safety, development efficiency, and sufficient speed. We’ve run WingCash successfully in PyPy, although it ran significantly more slowly in PyPy than in CPython. I’m not sure why.
We’re interested in getting WingCash running on Python 3. The main barrier is probably Formish, a library that will probably never be ported. Fortunately, we’ve been writing most forms using Colander and Deform, both of which work in Python 3, but unfortunately, a few forms are still based on Formish. I would personally enjoy the opportunity to banish Formish from WingCash since I’ve had trouble with it.
Do others see Python 3 as a priority yet? I’m not sure. Python 2 will be deprecated in a few years, so we need to do the port, but I’m not sure how soon is appropriate. For now, I’m editing the code with Sublime Text 3, which highlights some parts of the code that are incompatible with Python 3.