Complex sentence: The TeachText application is a simple text editor made by Apple Computer bundled with System 7.1 and earlier, and was one of the only applications included with the Mac system software, leading to its most frequent role as the application to open "ReadMe" files.
Split into simpler sentences: The TeachText application is a simple text editor made by Apple Computer bundled with System 7.1 and earlier. It was one of the only applications included with the Mac system software, leading to its most frequent role as the application to open "ReadMe" files.