While parent's "many many megabytes" might be an overstatement, today's editors are expected to display any number of languages and alphabets simultaneously, us

While parent's "many many megabytes" might be an overstatement, today's editors are expected to display any number of languages and alphabets simultaneously, using user-configurable, scalable, variable-width fonts that render in a variety of different resolutions with sub-pixel smoothing. Things like that add to the complexity of both the OS and the application itself.