Called , the tool is a plug-in that runs a set of tests and measurements. They are designed to give developers a detailed view of the rendering process of a Web page, from the moment it leaves a Web server to the moment it's fully displayed on a browser.

For example, MSFast measures CPU and memory usage, takes screenshots of the page white it's rendering, and captures and estimates download and rendering time for individual page sections and files on different bandwidths and connection speeds. MSFast also flags code that doesn't comply with accepted best practices for performance.

MySpace will release an early version of MSFast Tuesday at , an event focused on Web performance, in San Jose, California. This "pre-alpha" version of MSFast will work on Internet Explorer 6 and later versions.

"Leveraging the open-source community will really help us improve this tool," said Chris Bissell, MySpace's chief software architect, in an interview.

It's also a way to contribute back to the Web performance community, from which MySpace has learned a lot in recent years. It has applied those lessons and best practices to the work of tuning and optimizing its massive social networking site, Bissell said.