Keeping your system up to date usually involves invoking multiple package managers. This results in big, non-portable shell one-liners saved in your shell. To remedy this, topgrade detects which tools you use and runs the appropriate commands to update them.

ICESword is the great rootkit detection tool.

Quickly create and run optimised Windows, macOS and Linux desktop virtual machines. - GitHub - wimpysworld

A cross-platform (Windows, Linux, Mac) hex editor for reverse engineering, and everything else.

When your computer is getting full, BleachBit quickly frees disk space. When your information is only your business, BleachBit guards your privacy. With BleachBit you can free cache, delete cookies, clear Internet history, shred temporary files, delete logs, and discard junk you didn't know was there. Designed for Linux and Windows systems, it wipes clean thousands of applications including Firefox, Adobe Flash, Google Chrome, Opera, and more. Beyond simply deleting files, BleachBit includes advanced features such as shredding files to prevent recovery, wiping free disk space to hide traces of files deleted by other applications, and vacuuming Firefox to make it faster. Better than free, BleachBit is open source.