Transcrypt is a tool to precompile a fairly extensive subset of Python into compact, readable Javascript. It has the following characteristics:

• Allows for classical OO programming with multiple inheritance using pure Python syntax, parsed by CPython's native parser
• Seamless integration with the universe of high-quality web-oriented JavaScript libraries, rather than the desktop-oriented Python ones
• Hierarchical URL based module system to prevent name conflicts
• Simple relation between Python source and generated JavaScript code, combined with sourcemap support, for easy debugging
• Compact downloads, kB's rather than MB's
• Lightning fast JavaScript code, using memoization (call caching) to optionally bypass the prototype lookup chain
• Operator overloading can be switched on and off locally to facilitate use for numerical math that's both readable and efficient

Take a look at the documentation with code examples at the Transcrypt website: http://www.transcrypt.org .

First release with sourcemaps! Single level sourcemap support for Google Chrome has been added, allowing you to debug Python sources from non-minified JS target code. Extensive tests on both Windows and Linux have lead to the conclusion that Transcrypt is ready for production use. Thanks to everyone who filed bug reports! You submit them as GitHub issues at: https://github.com/JdeH/Transcrypt .

• Single level sourcemaps
• Div. bug fixes guided by submitted issues + autotest-cases added for them

• No standard libs, use or encapsulate the JavaScript ones, that's part of the concept. Some may be ported though.
• Not all methods of builtin types are there by default. This results from a deliberate choice to keep Transcrypt lean. Such things can be distributed in separate libs.
• No eval and exec of Python code. This is again part of the concept. Transcrypt code is compiled, optimized and minified in advance to warant fast page loads.
• No threading of any kind. Will probably stay that way as long as JavaScript doesn't properly support that.
• No iterator, generator, xrange stuff. Maybe in the future if a broadly installed version of JavaScript suppports it.

• None

As can be seen below, there's a simple parallel between the Python and the JavaScript code. So it should be easy to debug. Also, code can be tested from the command prompt using stubs.

• Multi-module Python source code obfuscator: https://pypi.python.org/pypi/Opy
• PLC simulator with Arduino code generation: https://pypi.python.org/pypi/SimPyLC
• A lightweight Python course taking beginners seriously (under construction): https://pypi.python.org/pypi/LightOn
• Event driven evaluation nodes: https://pypi.python.org/pypi/Eden
• Numscrypt (under construction, very early stage), experimental port of a microscopic part of NumPy to Transcrypt, using JavaScript typed arrays: https://pypi.python.org/pypi/Numscrypt