An alternative is to link certain directories under
/usr/local. For instance, to use
IDL, you'll need to:
ln -s /a/usr/local/rsi /usr/local/rsi
ln -s /a/usr/local/flexlm /usr/local/flexlm
ln -s /usr/local/rsi/idl/bin/idl /usr/local/bin/idl
(other soft links can be made to idlde, idlhelp, etc)
You need flexlm to access the license server (on draco) to run idl
(this is done in the background when you try to run idl).
You'll need to authenticate to be allowed to access the
license server on draco.