Choosing 'Open' from the 'File' menu lets you choose any TEXT or EPSF file. When you open a file this way, a new window is created, it is presented to Ghostscript for interpretation. This (usually) results in rendering the first page of the file into the window.
If there are more pages in the file, you will see a small alert box with two buttons: 'Next Page' and 'Interrupt'. Clicking the first will clear the window and let Ghostscript continue on with the next page in the file. Clicking the second asks Ghostscript to cancel processing the rest of the file.
Once a file has been rendered, it stays on the screen. You can resize, scroll it, save it (as a PICT file), copy it (to the clipboard). You can have as many windows open as memory allows.
