FreeEOS is a software library for calculating an equation of state for conditions in stellar interiors. The latest stable version of this library source code, FreeEOS-2.2.1, has been released on 2008-07-08.
The new release fixes all known bugs in FreeEOS-2.2.0 and has negligible changes (see http://freeeos.sourceforge.net/2.2.1-2.1.0.png\) compared to FreeEOS-2.1.0, the last recommended release of FreeEOS. Calculations based on the new release converge for conditions significantly more dense than a 0.1-solar mass model, the approximate convergence limit for FreeEOS-2.1.0. However, the EOS1 free-energy model needs adjustment (still a work in progress) before it can produce smooth results at such high densities.
The new release has been tested extensively on a modern Linux platform (Debian testing) with the gfortran-4.3.1 compiler and less extensively on that same platform with the g77-3.4.6 compiler. See http://freeeos.sourceforge.net/announcement-2.2.1.html for more details about the release and its testing.