Online communities—including various subcultural and identity-based groups—have become important spaces for collaboration, identity building, and public discourse. However, they often face challenges such as member attrition, polarization, the spread of misinformation, and the weakening of core values, which may be exacerbated by platform design or technological shifts such as AI-generated content and algorithmic governance. This project aims to examine the key issues in the evolution of such communities and explore how emerging technologies, including artificial intelligence and human-computer collaborative design, can foster their sustainable and inclusive development. The research will combine data analysis, case studies, and prototype design to evaluate the impact of technological interventions on factors such as community engagement, sustainability, and the information ecosystem.