The new version of Gmail has added many features strongly requested by users, and has made great improvements in the interface and performance. For example, brand-new contact management, enhanced chat module, faster page access speed, colored labels, etc. However, these still do not meet the personalized requirements of many users, and through the flexible Greasemonkey add-on in Firefox, we can achieve many functions that Gmail does not originally have. Since Gmail has restructured its code, many of the previous Greasemonkey codes that enhanced Gmail's functions have become ineffective. Fortunately, most of the authors of these codes have quickly followed up and released upgraded versions.