libecl is a package for reading and writing the result files from the Eclipse reservoir simulator. The file types covered are the restart, init, rft, summary and grid files. Both unified and non-unified and formatted and unformatted files are supported.
libecl is mainly developed on Linux and OS X, in addition there is a portability layer which ensures that most of the functionality is available on Windows. The main functionality is written in C/C++, and should typically be linked in in other compiled programs. libecl was initially developed as part of the Ensemble Reservoir Tool, other applications using libecl are the reservoir simulator flow and Resinsight from the OPM project.
In addition to the compiled C/C++ code there are Python wrappers which make most of the libecl functionality available from Python. For small interactive scripts, forward models e.t.c. this is the recommended way to use libecl functionality. You decide wether to build include the Python wrappers when configuring the cmake build - pass the option -DENABLE_PYTHON=ON to enable Python wrappers, by default the Python wrappers are not included.