I am here not talking about Server-side improvements. I am here talking about Front-End improvements that really affects the web page speed.
The time spent till the website is running on the client’s browser. If we analyze that time, we will get:
Request Time (in milliseconds)
Server Process Time, or response time (usually in milliseconds)
Downloading web page and files into browser (few to several seconds, depending on internet speed)
Rendering on browser.
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It has syntax coloring, folding, background syntax checking, auto-complete and calltips. It also includes libraries for autocompletion for jQuery, Ext JS, Ruby on rails and more.
I just recommend Komoodo Edit.