Bank Street Writer
Bank Street Writer was a 1980s word processor created at Bank Street College, where the Bank Street Reader series of schoolbooks were produced earlier. It was released for a number of platforms, including Commodore and Atari 8-bit systems as well as the Macintosh and IBM PC, but the Apple II version appears to be the most successful. Unlike some other word processors of the day which used text mode, Bank Street Writer was implemented in graphic mode, thus avoiding some of the character set limitations of the platforms it ran on, such as the lack of lowercase letters in early Apple computers.
Bank Street Writer had the ability to save files in plain ASCII (which would maximize portability of the files while not necessarily preserving all formatting) or in its native format. In its day, word-processor native formats were generally plain text with some embedded control or escape codes if printer-formatting features were used; the Bank Street Writer manual indicates that some control codes were user-customizable, so the embedded characters and their interpretation could depend on user configurations. It's also been reported that the Apple II version saved text in the "high-bit-set" mode, so it might be necessary to subtract 128 from the byte values to get normal ASCII.