Over the summer we've done a lot of work on cleaning up some of our software environment.
In the past we always attempted to make all installed software available to everyone in an automatic manner, but this often led to various problems - setting up one piece of software can interfere with another.
To avoid this, we've taken a lot of software out of the default PATH and put it into “modules” instead. This lets you type a command to add a given piece of software to your environment. You can find out more about the modules system here.
A major benefit is that you can also deactivate the piece of software after you're done with it, and in some cases you can request a specific version.
Software affected by this change includes:
/usr/local/bin, which allow packages to run without loading a module, are expected to disappear during October!