Depending on what you want to change, there are two paths you should look at.
For Manage only, there is a custom JSP now that you can enable (How to display the user name and site information in the Maximo Application Suite Manage?). By default it displays user and insert site but unlike other JSP files, this is intended to be replaced by the customer to surface whatever information you want. You mentioned "running text" so I assume this is what you'll need to use.
If you want something more global across MAS applications (like Monitor), they've enabled some UI configuration options including icons, text, CSS changes, etc. that you can see here: Updating the user interface - IBM Documentation .
------------------------------
Steven Shull
Naviam
------------------------------