Tax holiday eligibility for software exports: on site development by units still qualifies if the unit produces and exports the software. Where a unit located in an EPZ/EOU/STP produces software and exports it, development of the software at the client's premises does not disqualify the unit from the five year tax holiday, provided the software is a product of the unit and the statutory conditions are fulfilled. The 1993 Explanation that produce includes computer programmes is clarificatory and does not withdraw benefits from software exporters in EPZs/EOUs for years prior to the amendment.