gretl is an econometrics package, including a shared library, a command-line client program and a graphical user interface.
gretl offers an intuitive user interface; it is very easy to get up and running with econometric analysis. Thanks to its association with Ramanathan's Introductory Econometrics the package offers many practice data files and command scripts. These are well annotated and accessible.
You can choose your preferred point on the spectrum from interactive point-and-click to batch processing, and can easily combine these approaches.
gretl's home platform is Linux, but it is also available for MS Windows. I have compiled it on AIX and it should work on any unix-like system that has the appropriate basic libraries (see Appendix B).
The full source code for gretl is available to anyone who wants to critique it, patch it, or extend it. The author welcomes any bug reports.
gretl offers a full range of least-squares based estimators, including Two-Stage Least Squares. It also offers (binomial) logit and probit estimation, and has a loop construct for running Monte Carlo analyses or iterated least squares estimation of non-linear models. While it does not include all the estimators and tests that a professional econometrician might require, it supports the export of data to the formats of (GNU R) and (GNU Octave) for further analysis (see Appendix D).
gretl does well on the NIST reference datasets. See Appendix C.
gretl can access and fetch databases from a server at Wake Forest University. The MS Windows version comes with an updater program which will detect when a new version is available and offer the option of auto-updating.
gretl will produce its output in English, Spanish or French, depending on your computer's native language setting.