Packages

The easiest way to obtain Python enabled clingo packages is using Anaconda. Packages are available in the Potassco channel. First install either Anaconda or Miniconda and then run: conda install -c potassco clingo.
Packages for clingo are available in the Linux distributions Debian, Ubuntu, and Arch Linux. (For historic reasons, the clingo package is split into gringo and clasp on Ubuntu/Debian.)
For Mac OS X, clingo packages are available in homebrew and macports.

Changes

change C API to use numeric instead of symbolic literals
- affects assumptions and assigning/releasing externals (breaks backward compatibility)
- added overloads to C++, python and lua API to support both numeric and symbolic version (preserves backward compatibility for most code)
the python, C and C++ APIs now allow for customizing clingo by implementing a custom main function but reusing the rest of the application including the standard output
add API function to detect conflicting programs
add message logger to python and lua interface
add support for primes in the beginning of identifiers and variable names
add per solver registration of watches during propagator initialization
add a directive to selectivel suppress undefined atom warnings
add support for user defined statistics
add _to_c functions for python API to be able to call C functions from python
only create ground representations for requested program parts when grounding (#71)
improve program observer (#19)
support for binary, octal, and hexadecimal numbers (#65)
the backend has to be opened/closed now
release python's GIL while grounding (#82)
TruthValue.{True,False} becomes TruthValue.{_True,_False} in python API
improve API and it's documentation