the lead dev is a freeze peach absolutist. he's said some ignorant shit about trans people and when people said "hey, let's adjust this language" he was like "let's not get political"
These are browser engines, or at least software for rendering HTML but not necessarily the actual browser. I don’t know them all, but top left, Gecko, is the engine for Mozilla, center is Web Kit for Safari, bottom center is Chromium for Chrome, Brave, Edge, etc., and bottom right is Trident, the old engine for Microsoft Internet Explorer.
The engine makes it so HTML, CSS, JavaScript etc. are downloaded and turned into pixels you can look at. The browser embeds an engine for that purpose, but then also has a URL bar, tabs, bookmarks, a history feature and so on.