This paper identifies important technological, financial, and equity challenges to the development and implementation of online or onscreen educational testing. The insights are based on the author's experiences in New Zealand of being the senior project manager for the Assessment Tools for Teaching and Learning (asTTle) computer-based standardised testing system. The system was funded by the government for formative educational purposes and is delivered to schools for free. The issues faced in the project that need to be considered in any new online testing system include: clarity about the purpose of the testing system, the importance of knowing the current technology conditions, the challenges of working within the dynamic and changing world of technology, the need to assure quality and equity for all test-takers, the economics of paying for a public, rather than commercial, service, and challenges in the management processes of developing and introducing a new system. This survey of technology issues makes it clear that moving to online or onscreen testing has many fishhooks in it that need substantial thought prior to engaging in the development process.