BT

New Early adopter or innovator? InfoQ has been working on some new features for you. Learn more

Yahoo! Has Open Sourced YSlow

| by Abel Avram Follow 4 Followers on Feb 18, 2012. Estimated reading time: 1 minute |

Yahoo! has decided to open source YSlow. Developers no longer need to submit feature requests to Yahoo!, being able to improve the tool themselves. Comparing YSlow with Google Page Speed.

After many years of making it freely available under Mozilla Public License MPL 1.1, Yahoo! has decided to open source YSlow under a BSD license. The Yahoo! Exceptional Performance group used to gather feedback from the community in order to improve the tool. Developers can now do whatever they want with the tool. Marcel Duran, a Yahoo! Frontend Engineer who’s been in charge of the project, has made the YSlow code available on GitHub, inviting developers to fork the code and make pull requests that will later will be merged back into the development repository if accepted. Duran will also update the add-ons across all supported browsers. From now on, the community will no longer depend on Yahoo! to implement certain feature requests.

YSlow is a web page performance tool similar to Google’s Page Speed which was open sourced back in 2009 under an Apache 2.0 license. There are some differences between the tools. While YSlow has add-ons for Firefox, Chrome, Safari, Opera, including the mobile versions via a bookmarklet, and also can be executed at the command prompt, Page Speed has extensions only for Chrome and Firefox. But Page Speed comes with a service for analyzing web pages, including those targeted at mobile devices. Page Speed also has an Apache module for optimizing pages by rewriting various page resources, HTML, JavaScript, CSS, JPG, PNG.

Both tools analyze pages on a set of rules listed below:

 Besides analyzing the pages, the tools suggest changes that are meant to improve the web page loading speed.

Rate this Article

Adoption Stage
Style

Hello stranger!

You need to Register an InfoQ account or or login to post comments. But there's so much more behind being registered.

Get the most out of the InfoQ experience.

Tell us what you think

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Email me replies to any of my messages in this thread
Community comments

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Email me replies to any of my messages in this thread

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Email me replies to any of my messages in this thread

Discuss

Login to InfoQ to interact with what matters most to you.


Recover your password...

Follow

Follow your favorite topics and editors

Quick overview of most important highlights in the industry and on the site.

Like

More signal, less noise

Build your own feed by choosing topics you want to read about and editors you want to hear from.

Notifications

Stay up-to-date

Set up your notifications and don't miss out on content that matters to you

BT