This document summarizes the Sahana Taiwan organization and its work developing open source disaster management software. It discusses the Python rewrite of the original PHP-based software using the Web2Py framework. The rewrite aims to improve maintainability, integration of mapping and messaging features, and a more interactive web interface. The document also describes Sahana's use in response to the 2010 Haiti earthquake and how the software and community have continued to evolve and engage volunteers.