Pycopy is a minimalist, lightweight, resource-efficient implementation of Python(-like) language. Pycopy to CPython is the same thing as Scheme to Common Lisp. Executable sizes of 300-400KB, instant startup, no need to carry around large monolithic library consisting largely of legacy modules - some but not all of Pycopy's features.
Pycopy 3.x release solves the question of extensibility of Pycopy builtin types (which by default provide subset of CPython functionality) to full CPython compatibility. A couple of pretty large Python applications, originally developed for CPython, now can run with Pycopy.
Prebuilt binaries of this release are available at https://github.com/pfalcon/pycopy/releases/tag/v3.0.5
More details about Pycopy -------------------------
Pycopy strives to define a core language features suitable to easily develop efficient software, while allow for extensibility to a wider (and much more bloaty and less efficient) set of features for compatibility with existing software.
Pycopy doesn't come with bulky hazardous lead-acid batteries. Instead, a set of a few core modules are included builtin: inspired, being a noticeable subset, and a little bit of extension, of the corresponding CPython modules - clearly namespaced, to still allow room to implement fully compatible CPython modules. These new modules aren't intended to be an adhoc thing, just an alternative API with a constraint of minimality. Implementation of that API also exists for CPython (WIP), allowing Pycopy -> CPython compatibility.
The rest is handled outside the core language, via a separate project, pycopy-lib: https://github.com/pfalcon/pycopy-lib , which strives to port CPython stdlib to Pycopy, while, where needed, provide more lightweight module variants and extensions.
Pycopy is a full-stack project, with ecosystem including a web micro-framework, pure-Python Python parser, FFMPEG bindings, SDL bindings, LLVM bindings, etc.: https://github.com/topics/pycopy