Complex sentence: He is also known for his role in the creation of the IMAP mail protocol, and for writing the ttyftp serial line file transfer program, which was developed into the MacIntosh version of the Kermit protocol at Columbia University.
Split into simpler sentences: He is also known for his role in the creation of the IMAP mail protocol. Bill also wrote the ttyftp serial line file transfer program, which was developed into the MacIntosh version of the Kermit protocol at Columbia University.