Ss (pronounce /ɛsɛs/; other name "Serĉi" (Sercxi), pronounce /ˈsert͡ʃi/), previously called Searxes, is the world's first anti-cloudflare search engine website for Tor users and clearnet users, operating since year 2016.
Some people may think about Schutzstaffel on first sight but do not get confused; the second letter s is lowercase taken from previous name.
It is fed by quality sources and rank down Cloudflare sites to bottom by default, thus you avoid the risk and inconvenience of having MITM traps littered throughout search results. You can also open a cached version of the page by clicking the icon of the search result. There are many options to choose from for example disabling Cloudflare ranking and rank down known Tor-hostile sites. Ss is also providing public API service for developers and also Lynx-site for text-base browser users.
The current Ss logo resembles an umbrella. Developers said that they want to provide an umbrella to protect people safe against heavy rain caused by the cloud.
About .onion certificate warning
Tor Browser user may see this warning on first visit.
Warning: Potential Security Risk Ahead Tor Browser detected a potential security threat and did not continue. Someone could be trying to impersonate the site and you should not continue.
You can ignore this warning because onion service is already encrypted. There are multiple reasons to use HTTPS over Tor. At the moment the only way to get a trusted SSL certificate for a .onion domain is to buy an EV (extended validation) certificate.