YSlow is now open source
github.com
github.com
(Update: Aha, there's a blog post at http://developer.yahoo.com/blogs/ydn/posts/2012/02/welcome-y... - it doesn't explain much to do with my question but it seems becoming BSD makes it more open source than under the Mozilla Public License? :-))
They append Y to anything. So there's usually names like YCoolThing. And you go about "why you are questioning CoolThing?!"
but YSlow is just perfect.
How can you read Y as Why? Is it WhyCombinator for you?