[docs] Clarify meaning of "superset of Python" · modular/modular@cb307d0

migrating developers to new compilers and languages, and we leverage the

existing MLIR compiler ecosystem.

Further, we decided that the right _long-term goal_ for Mojo is to provide a

**superset of Python** (that is, to make Mojo compatible with existing Python

Further, we decided that the right _long-term goal_ for Mojo is to adopt the

**syntax of Python** (that is, to make Mojo compatible with existing Python

programs) and to embrace the CPython implementation for long-tail ecosystem

support. If you're a Python programmer, we hope that Mojo is immediately

familiar, while also providing new tools to develop safe and performant

## Python's problems

By aiming to make Mojo a superset of Python, we believe we can solve many of

Python's existing problems.

By aiming to make Mojo the best way to extend Python, we believe we can solve

many of Python's existing problems.

Python has some well-known problems—most obviously, poor low-level performance

and CPython implementation details like the global interpreter lock (GIL),

drives fragmentation, and incompatibility makes _migration_ difficult to

impossible—recall how challenging it was to migrate from Python 2 to Python 3.

### Python supersets with C compatibility

### Python family languages with C compatibility

Because Mojo is designed to be a superset of Python with improved systems

programming capabilities, it shares some high-level ideas with other Python

supersets like [Pyrex](https://wiki.python.org/moin/Pyrex) and

[Cython](https://cython.org/). Like Mojo, these projects define their own

language that also support the Python language. They allow you to write more

Because Mojo is designed to adopt the syntax of Python with improved systems

programming capabilities, it shares some high-level ideas with other members of

the Python family of languages like [Pyrex](https://wiki.python.org/moin/Pyrex)

and [Cython](https://cython.org/). Like Mojo, these projects define their own

language while also supporting the Python language. They allow you to write more

performant extensions for Python that interoperate with both Python and C

libraries.

These Python supersets are great for some kinds of applications, and they've

These Python family languages are great for some kinds of applications, and they've

been applied to great effect by some popular Python libraries. However, they

don't solve [Python's two-world problem](#the-two-world-problem) and because

they rely on CPython for their core semantics, they can't work without it,