The Design Pattern Library shares user interface design patterns vetted by Yahoo! with the web design and development community.
Apache Hadoop is an open source Java software framework for running data-intensive applications on large clusters of commodity hardware, allowing storage and retrieval of large distributed data sets.
Pipes is a powerful composition tool to aggregate, manipulate, and mashup content from around the web.
The YQL platform provides a single endpoint service that enables developers to query, filter, combine, execute and store data across Yahoo! and beyond.
YSlow is a Firefox add-on (integrated with the Firebug development tool) that analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.