When comparing Safari vs SeaMonkey, the Slant community recommends SeaMonkey for most people. In the question“What are the best desktop web browsers?” SeaMonkey is ranked 19th while Safari is ranked 22nd. The most important reason people chose SeaMonkey is:
Wraps all your internet stuff together. It's like it's Firefox and Thunderbird all wrapped into one, and it kinda is. It's the continuation of the project both of those were extracted from.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Works elegantly in OSX
The rendering of the pages and the browser compatibility with OSX works smoothly, when compared to other browsers. Also you get very high battery life with Safari, when compared to Chrome.
Pro Extremely fast
Pro Sleek design
– No distraction stuff like favicons in tabs, all that borders, bevels and embosses in panels like in other browsers, no ugly shaped tabs.
– Neat adress bar.
– Good looking start “show all tabs” screen.
Pro iCloud syncing
Tabs, passwords, bookmarks and, history all sync across devices.
Pro Safari uses Webkit, a great open source web engine
Webkit is very light compared to Blink, renders web pages at an incredible speed, great CSS support and is also constantly evolving.

Pro Full internet suite
Wraps all your internet stuff together. It's like it's Firefox and Thunderbird all wrapped into one, and it kinda is. It's the continuation of the project both of those were extracted from.
Pro Not bloatware
Pro Designed for usability, not looks
Cons
Con OSX only
Apple dropped Windows support after Safari 5.
Con Poor support for new web technologies
Safari usually takes its time when it comes to adopting new and useful web technologies meaning that the user gets an inferior experience compared to other modern browsers.
Con Proprietary
While Safari er is currently available gratis (without monetary charge) on Mac OS X, it is currently not libre (meaning that it does not allow users to view the source code used to create, to modify that code, or to redistribute modifications) and is therefore neither free nor open-source software.
Con Does NOT block Ads
Doesn't block ads, unlike browsers like Brave and Vivaldi.
Con Terrible support for open source formats like .VP9 or .ogg
Apple does not support open source formats. Instead, they use H.264 and H.265.
Con Even on OSX not the best Experience
Video controls are bad esp. on youtube. Only few browser extensions.
Con Outdated Rendering engine
All other browsers and toolkits (Qt/GTK) have shifted to Googles Blink-fork of KHTML/Webkit so Apple is currently the only main contributor left.
Con Looks very old and outdated
Con No Addons
not a single adblocker or privacy addon that was useful
Con Bloated with unnecessary features
Seamonkey has a browser, email client, and even an IRC chat. Too much bloat! It doesn't do one thing, let alone do anything well. It should be avoided.
