The boom in personal computer software sales by North American companies appears to have gone emphatically bust: after growing at 40% last year, up from 20% in 1987, they rose just 13.5% in the second quarter of this year according to the US Software Publishers Association – and it was only strong export growth that kept the rate in double figures – sales in the US and Canada were up just 8.8% to an estimated $658m over those for the same period a year earlier, measured by retail sales reported by 139 leading software publishers; international sales, for which no numbers were given, rose 27% to account for over 30% of the total business.