This Reprint gathers peer-reviewed original and review articles from the Computers Special Issue "AI in Its Ecosystem". Instead of focusing on separate AI algorithms, it treats AI as an interconnected technological ecosystem with three core themes: multi-type computing platforms for AI operation, foundational enabling technologies for AI creation, and cross-sector intelligent real-world deployments. Covered infrastructures contain distributed parallel systems, cloud, edge, fog, quantum computing and IoT. Key supporting tools cover advanced optimization, standard data pipelines and novel hardware-software frameworks. The papers deliver interdisciplinary cases: medical diagnostic AI, surgical object identification, traffic forecasting, banking AI assistants, generative art, auto code tools and electromagnetic computation. Every study uses strict benchmarks, quantitative metrics and repeatable tests to prove model stability and efficiency. Overseen by an international editorial group specializing in medical LLMs, computer vision, wireless signals and high-performance computing, this Reprint is a unified, replicable reference for computer scientists, AI programmers, medical staff and industrial engineers. It collects verified leading AI advances to boost academic exchange, ease intelligent system design and speed up AI practical adoption across engineering, medical, social and physical sciences. Read more