A significant impediment to third-party software on the Lisa was the fact that, when first launched, the Lisa Office System could not be used to write programs for itself. A separate development OS, called Lisa Workshop, was required. During this development process, engineers would alternate between the two OSes at startup, writing and compiling code on one OS and testing it on the other. Later, the same Lisa Workshop was used to develop software for the Macintosh. After a few years, a Macintosh-native development system was developed. For most of its lifetime, the Lisa never went beyond the original seven applications that Apple had deemed enough to "do everything", although UniPress Software did offer UNIX System III for $495.