This program converts a plain running text into one-sentence-per-line format by simply adding a return code after the standard sentence terminal marks. The current version (ver. 2) covers most common and frequently-used abbreviations such as Mr., Dr., Prof., a.m., p.m. as well as sentence-initial list numbers, but you still have to post edit the results manually for other less common abbreviations. Note that when initials are followed by the "period + space" combination as in G. W. Bush the strings containing them will be divided immediately after the period mark, resulting in improper segmenetation in most cases. Also note that all strings must be terminited to be considered an indepenedent sentential unit.
http://www.someya-net.com/00-class09/sentenceDiv.html
http://www.someya-net.com/00-class09/sentenceDiv.html