@Krish1980 While `font-smoothing` only works on Macs, `optimizeLegibility` has nothing to do with anti-aliasing. It enables OT features. I’m betting this has to do with a poor font choice for screen use.
PS and Fireworks have four different settings that render type. Browsers don’t have this option. There are many causes for a font not to render well in the browser. This can be anything from the type designer choosing to auto–hint (manual hinting is a long and tedious process) which usually causes the font to look poor, more noticeably in small sizes (you see this a lot with GWF). Different font files can cause this as well (TrueType vs PostScript). Chrome also has a bug not rendering anti-aliasing correctly. So there’s not always one “thing” at fault.
Oops, I forgot about this discussion. The reason the script appears choppy is because you are using it at small sizes. It’s a display face which are usually not optimized for this use. I also don’t see Arial being used but rather Pontano Sans. Pontano Sans is also a display face and even though the designer states you can use it for text type, it clearly doesn’t render well.