theHarvester
Security & privacy
Collects public information such as subdomains and hosts.
Available for macOS, Linux

An open-source intelligence (OSINT) automation tool.
Official source: github.comLast verified: awaiting review · How we check softwareDeveloper: SpiderFoot project
SpiderFoot automates gathering publicly available information about domains, IP addresses and organisations, for authorised assessments and threat intelligence.
Open Source Open Source
Open source: the source code is public, so anyone can inspect it, and it's free to use.
Prices change, so check github.com for current pricing.
There's no verified package-manager install for SpiderFoot yet. Get it from github.com.
No alternatives listed yet.
Security & privacy
Collects public information such as subdomains and hosts.
Available for macOS, Linux
SpiderFoot is open source.
SpiderFoot is available for Windows, macOS and Linux. It isn't available for Android and iPhone & iPad.
From the official website, github.com. Aptorise links only to official sources and never hosts installers.