File > Send to Softimage

NoteSend to Softimage is only available in the Maya File menu if you have matching versions of Maya and Softimage. (Maya 2013 and Softimage 2013 are matching versions.)

Send as New Scene: Opens a new scene in Softimage, and sends the selected objects from Maya.

This option launches Softimage if it is not already running. If already running, Softimage prompts you to save the current scene or cancel. Selecting Cancel stops the send operation.

You must select at least one object to send to Softimage, otherwise you are prompted to send the entire scene. If you select a specific object to send, the object is automatically sent in subsequent updates if no other objects are selected.
Update Current Scene: Available only if Softimage is running. Updates the Softimage scene by sending the current Maya selection. If no objects are selected, Maya attempts to resend any previously sent objects.
Add to Current Scene: Available only if Softimage is running. Sends the current selection to Softimage. Any selected objects that have been previously sent are duplicated in the Softimage scene.
Select Previously Sent Objects: Selects any objects previously sent to Softimage.

This option is a convenient way to see which objects are already being shared, and to choose which objects to add to the selection.