audio-visual contractors (supply and operation of specialist audio-visual equipment).
telecommunications companies (videoconferencing/teleconferencing/satellite conferencing).
transport operators (airlines, coach and rail companies, car hire, taxi firms, ferry companies).
interpreters and translators (for international conferences).
after-dinner speakers, entertainers, corporate events companies
specialty caterers (banquets, receptions, buffets).
floral contractors (flower displays for conference platforms, registration areas, exhibition stands).
exhibition/exposition contractors.
companies which develop specialist computer software (e.g. venue-finding and event management programmers).