Mulberry began life as a Macintosh IMAP client but now has versions for Windows and Linux as well. It also supports a host of e-mail protocols as well as scheduling and calendaring functions.
Daboo launched the program while at the University of Cambridge in England, but now lives in Pittsburgh. He bought the program assets out of bankruptcy when Isamet, the development company, went bankrupt in 2005.
Whether that is enough to secure its future is now up to the community.