With the discontinuing of the old Presto-based Opera browser (a pity), the browser "industry" has shrunken down to three main lineages.
- The "Navigator" line (based on the Netscape Navigator from 1994), that today includes Mozilla Firefox and Seamonkey, as well as the stock browser of the niche mobile system Sailfish OS. All these browsers use the Gecko rendering engine and reach a market share of 10-20% (and decreasing).
- The "Explorer" line which mainly includes the Internet Explorer and its successor, Microsoft Edge, is using the Trident engine and its successor EdgeHTML, respectively. EdgeHTML is based on Trident, but does not include all the backwards compatibility code which enabled IE11 to still display corporate intranet websites written for IE5 and IE5 only.
- The "Konqueror" line started with a rather unknown browser: Konqueror, the stock browser (and former file manager) of KDE, a desktop environment for Linux and BSD. Apple based its Safari browser on Konqueror's KHTML engine and forked it into WebKit, which is now the dominant engine on mobile devices (iOS actually does not allow any other engines - that's why Firefox for iOS was not released until 2015, then based on WebKit as well). Google then forked WebKit into Blink for its Chrome browser. Blink is now being developed by Google (Chrome) and Opera, as Opera Software stopped developing their browser in 2013 and started with a new browser based on Chrome.
There are also a few other browsers such as Dillo, NetSurf, and Opera Mini, which use their own rendering engines, but their market share is negligible.
If you spot any error, please write a comment.