Metal slivers (not unlike USBs) which contain code that people can insert into ports in their head, modifying their vision and their cognitive abilities.
Microsofts Term Timeline in Neuromancer
The timeline below shows where the term Microsofts appears in Neuromancer. The colored dots and icons indicate which themes are associated with that appearance.
...are young with a carbon socket behind their left ear, into which they can insert microsofts. Molly greets one seller, a young man with several microsofts. Larry adds another as she... (full context)