The Mojo language is still very young,
The Mojo standard library, compiler, and runtime are not available for local development yet, so we created a hosted development environment where you can try it out. We call it the Mojo Playground!
To provide the best experience possible, the Mojo Playground currently supports a limited number of people. We plan to scale up quickly so everybody can get access over time.
The Mojo programming language aims to be fully compatible with the Project Jupyter ecosystem. It's not yet fully source-compatible with Python code, only providing a subset of its syntax, e.g. missing keyword arguments for functions, the global keyword, and list and dict comprehensions. Further, Mojo also adds features that enable performant low-level programming: "fn" for creating typed, compiled functions and "struct" for memory-optimized alternatives to classes. A struct in Mojo is similar to a Python class: they both support methods, fields, operator overloading, decorators for meta programming. Mojo can call existing Python 3.x code by reusing the CPython runtime. Modular plans to add integration to transparently import Clang C/C++ modules and transparently generate a foreign function interface between C/C++ and Mojo.
Mojo has a borrow checker, an influence from Rust, and in that way is dissimilar to Python.
Mojo is a new programming language that bridges the gap between research and production by combining the best of Python syntax with systems programming and metaprogramming.