Pale Moon 15 is a customised version of Firefox 15, which has been carefully optimised for speed and efficiency.
The program has been made more lightweight, for instance, by 
stripping out little-used components like the accessibility features, 
and the parental controls. The crash report has also been stripped out, 
as it's designed to work with server-side technology that isn't 
available on palemoon.org. And Pale Moon also drops support for Internet
 Explorer's ActiveX and ActiveX scripting technology, which also offers a
 security benefit as it means the browser can't be infected by malicious
 ActiveX controls.
Other optimisations are more technical. In particular, Firefox is 
compiled with the most conservative of settings, to ensure that it'll 
run on even ancient CPUs. Pale Moon, though, is optimised to take full 
advantage of modern processors, and this can give it a huge advantage 
over Firefox in some areas.
So how much faster can the browser be? That's a tricky question, as performance varies greatly depending on what's being tested.
And there are other tweaks, too. Pale Moon's developer reports that 
issues with native OpenGL rendering were "causing poor performance on a 
number of systems", and so Pale Moon's WebGL 3D will now use DirectX if 
possible instead, further improving speeds.
The browser does have one potential down side, in that it may be 
incompatible with some extensions. If they've assumed that the browser's
 program name is firefox.exe, say, or they're using components that Pale
 Moon has stripped out, like the Parental Controls, then you'll probably
 find they don't work.
This is rare, though - more extensions install and run just fine. 
Trying out Pale Moon also gets you access to useful extras, like the 
Language Packs (you can now run the program in more than 70 languages), a
 portable edition, and a 64-bit version. And as you can install and run 
both Pale Moon and Firefox together on the same system, the program is 
really easy to evaluate. So if any of this sounds right for you, then 
give Pale Moon a try, and see how much faster it might be on your 
system.
What's new:
 This is an update to address a number of performance, stability and security issues, as well as some added features.
      
Fixes:
      
Fixes:
- Important performance regression fix. Both javascript and the layout engine should now have the speed and stability that is to be expected from an optimized browser.
- Fix for the "tabs on top" menu entry not showing when tabs are already set on top, making it very difficult to switch them back to bottom.
- Crash: Fix for a browser crash with certain types of invalid gradients. (bug #792903)
- Security: Prevent private browsing data leakage through popup windows (bug #795015)
- Security: Detect IC purging (bug #794025)
- Security: Prevent mRules from dying in DoInsertHTMLWithContext (bug #788950)
- Security: Drain the parent frame's overflow list before insert/append (bug #765621)
Features:
- Redesigned the identity panel and the way secure sites are handled in the UI
 You will now always get the favicon in the address bar, and on secure sites you will have an added padlock (indicating ssl, extended verification or a broken/insecure/mixed-content site) to the identity panel and colored shading around the URL to indicate the status. (see detailed changelog)
- After evaluating the new address bar autocomplete algorithm, it is now switched on by default.
- Added an option to easily switch address autocompletion on or off (see detailed changelog)
- Partial implementation of Japanese "status bar" preferences text
 



 
