Mac OS X Softwares to No installation required

Jitsi is a free and open-source suite of secure, flexible communication tools. It offers multi-platform support for voice (VoIP), video conferencing, and instant messaging, emphasizing privacy and ease of use with no account required to start a meeting.

VirusTotal is a free online service that analyzes suspicious files, URLs, domains, and IP addresses for malware and other security threats using numerous antivirus engines, website scanners, and blacklisting services. It aggregates findings from a diverse array of security tools, providing comprehensive reports for faster threat identification and analysis.

XAMPP is a free and open-source cross-platform web server package. It includes the Apache HTTP Server, MariaDB database, and interpreters for scripts written in the PHP and Perl programming languages.