The story
- Latincosta
- Latincosticāre
- Old Frenchcostoier
- Middle Englishcosteien
- Englishcoast
- Englishcoaster
- Proto-Indo-European*sem-
- Proto-Germanic*samþuz /*samftuz
- Proto-West Germanic*samft(ī)
- Old Englishsōfte
- Middle Englishsofte
- Englishsoft
- Proto-Germanic*warō
- Proto-West Germanic*waru
- Old Englishwaru
- Middle Englishware
- Englishsoftwarebf.
- English todaycoasterware
From coaster + -ware, from the jocular notion that the disc containing the software is more useful as a drink coaster.
Etymology from Wiktionary, CC BY-SA 4.0.