Snowball is a small string-handling language, and its name was chosen as a tribute to SNOBOL (Farber 1964, Griswold 1968 ― see the references at the end of the introduction), with which it shares the concept of string patterns delivering signals that are used to control the flow of the program. See the Snowball manual on thais page.
You may also be interested in an English lemma list made in 1998 by Yasumasa Someya which "currently contains 40,569 words (tokens) in 14,762 lemma groups. It is still far from complete, but I hope you find the list useful in preparing your own more complete lemma list. If you have any questions or comments about this lemma list, feel free to contact me (ysomeya@gol.com)"