See the IDL_IDLBridge. It allows you to run multiple sessions of IDL so you can run a compute intensive process in the background without the blocking behavior you are seeing. Bill Okubo - IDL Product Manager

Thank you...but as far as i understood, IDL_IDLBridge doesn't allow parallel interactive interface usage. To illustrate, supposing that I have a set of 2 tabs, having a tree widget in one, and a table widget in the other, since they belong to the same parent widget, the processing of data in one tab will freeze all manipulations. Is there a way to allow parallel running within the same parent widget? Or should I opt for operations in separate windows as shown in the different examples that you've provided. Thank you,