The current LAMMPS tarball on SourceForge is the 15 May 2015 version.
Newer development LAMMPS tarballs are available for download from the
LAMMPS web site at lammps.sandia.gov. The 15May15 version is a stable
version within the last year. There may be newer stable versions on
the web site.
All documentation for LAMMPS is available on the LAMMPS web site.
All questions about LAMMPS should be posted to the LAMMPS mail list
(hosted by SourceForge); see lammps.sandia.gov/mail.html for info on
how to join the list, post to it, browse and search past threads, etc.
The SourceForge Forums for LAMMPS are not read by the LAMMPS
developers. Post questions to the mail list instead.