1.2. What does a LAMMPS version mean¶
The LAMMPS “version” is the date when it was released, such as 1 May 2014. LAMMPS is updated continuously and we aim to keep it working correctly and reliably at all times. You can follow its development in a public git repository on GitHub.
Whenever we fix a bug or update or add a feature, it will be merged into the develop branch of the git repository. When a sufficient number of changes have accumulated and the software passes a set of automated tests, we release it in the next patch release, which are made every few weeks. The release branch of the git repository is updated with every such release. Info on patch releases are on this website page.
Once or twice a year, we apply only bug fixes and small, non-intrusive changes to the develop branch and the code is subjected to more detailed and thorough testing than the default automated testing. The latest patch release after such a period is then also labeled as a stable version and the stable branch is updated with it. Between stable releases we occasionally release some updates to the stable release containing only bug fixes and updates back-ported from develop but no new features and update the stable branch accordingly.
Each version of LAMMPS contains all the documented features up to and including its version date.
The version date is printed to the screen and logfile every time you run LAMMPS. It is also in the file src/version.h and in the LAMMPS directory name created when you unpack a tarball. And it is on the first page of the manual.
If you browse the HTML pages on the LAMMPS WWW site, they will by default describe the most current patch release version of LAMMPS. In the navigation bar on the bottom left, there is the option to view instead the documentation for the most recent stable version or the latest version from the current development branch.
If you browse the HTML pages included in your tarball, they describe the version you have, which may be older.