Free Software Foundation
Grep for Linux
GratuitoGrep for Linux: Essential Command-Line Tool
LinuxeSpeak for Linux
GratuitoeSpeak for Linux: A Versatile Speech Synthesizer
LinuxM4 for Linux
GratuitoComprehensive Overview of M4 for Linux
Linux
GNU Emacs
GratuitoComprehensive Overview of GNU Emacs for Windows
WindowsSed for Linux
GratuitoSed for Linux: Streamlined Text Processing Tool
LinuxHASAS for Linux
GratuitoComprehensive Overview of HASAS for Linux
Linux