An empirical study of high-speed software development practices was conducted in US companies. Fast development, along with low cost and high quality has formed a tripartite tension among software engineering goals. The detailed case studies of Internet software development were reviewed in 10 companies and then knowledge was synthesized on best practice for quality and agility. Agile methodologies, including Extreme Programming and Scrum are found increasing in the software development field. Some of the problems identified in high speed software development, include demands of time-to-market compression, insufficient programmer productivity, ambiguous requirements, fluid requirements, lack of design time and experience, and changing environment. The solutions to the problems identified, include parallel development and frequent releases, greater reliance on tools and reusable components, production prototyping, customer implantation, multitiered architecture and emphasis on acquiring the right expertise and tailored methodology.