<p>From their website: "Otter Browser aims to recreate the best aspects of the classic Opera (12.x) UI using Qt5." Their motto is: "Controlled by the user, not vice versa". Version tested: 0.9.12 (SlackBuild from slackbuilds.org). Program used for testing requests: Mitmproxy.</p>
<p>Otter Browser <b><spanclass="lime">makes no unsolicited requests at all.</span></b> It is fully open source. The developers, also, don't plan to include any spyware "features" in the future. This seems like a true privacy-based web browser (at least for now).</p>