Lmod and XALT: Modules and Tracking Software use.

Lmod is a modern environmental module system for providing software to
HPC users.  XALT is a tool to track software usage in a lightweight
manor.  Both tools help in managing software on your HPC system.  Lmod
can track the modules users load.  XALT knows what programs and
libraries your user execute.

Lmod can help users handle complex software stacks by supporting the
software hierarchy.  Lmod support a cache to speed up module access
and a long list of other features such as user module collections,
module properties, semantic versioning etc. 

XALT tracks both MPI and non-MPI programs as well as the libraries
that users run.  Sites can know exactly what kinds of programs user
are running.  What percentage of programs are MPI based or non-MPI
based?  Are the kinds of program on your cluster solving Chemistry,
Physics, Biology or something else?
