Complex sentence: Seth Vidal and Michael Stenner did the original development of yum at Duke, while yup was originally developed and maintained by Dan Burcaw, Bryan Stillwell, Stephen Edie, and Troy Bengegerdes of Yellow Dog Linux.
Split into simpler sentences: Seth Vidal and Michael Stenner did the original development at Duke. It was then maintained by Dan Burcaw, Bryan Stillwell, Stephen Edie, and Troy Bengegerdes of Yellow Dog Linux.