Moved and updated LLPython (formerly LLNumba) documentation from Numba repository.

docs/source/doc/llpython/intro_llpython.rst

@@ -0,0 +1,46 @@
+====================
+Introducing LLPython
+====================
+
+In this article, we introduce the llpython package.  The primary goal
+of the llpython package is to provide a Python dialect/subset that
+maps directly to LLVM code.  LLPython differs from its originating
+LLVM translator, Numba, in the following aspects:
+
+  * LLPython code is not intended to work in Python if not translated
+    and wrapped.
+  * The LLPython translator only uses LLVM types.
+  * LLPython is explicitly typed, and does not support type inference.
+    LLPython does not support implicit casts, all casts must be explicit.
+  * LLPython supports code that directly calls the C API, the Python C
+    API, and the llvm.core.Builder methods.
+
+Additionally, we designed the sub-package to have the following
+engineering properties:
+
+  * Usable from Python 2.7, and 3.X.  At the time of writing, we plan
+    to support Python 2.6.
+  * Clean from Numba dependencies (other than llvmpy), and can be used
+    as a standalone code generator without a full Numba installation.
+  * Provides a series of Python bytecode passes that can be easily
+    used by other projects.
+
+
+LLPython Origins
+================
+
+We developed LLPython with the initial goal of simplifying writing
+LLVM code.
+
+
+LLPython Internals
+==================
+
+In this section, we describe the various passes performed by the
+LLPython translator.
+
+
+Conclusions
+===========
+
+LLPython is neat.