Complex sentence: Yellow Dog Linux lent its name to the popular yum Linux software updater; yum was derived from Yellow Dog's yup (Yellow Dog Updater) and thus called Yellowdog Updater, Modified.
Split into simpler sentences: Yellow Dog Linux lent its name to the popular yum Linux software updater. YUM was derived from Yellow Dog's Yup (Yellow Dog Updater) and thus called Yellowdog Updater, Modified.