The original vi editor

http://ex-vi.sourceforge.net/

The traditional 4.4BSD /bin/csh C-shell

Resolution tool for Intel i915 video cards

Port of various original plan9 tools

https://tools.suckless.org/9base

Fast pixel formats conversion library

Enhanced Printer Spooler

http://lprng.sourceforge.net/

High-performance CORBA ORB with support for the C language

High-performance CORBA ORB with support for the C language

High dynamic-range (HDR) image file format

http://www.openexr.org/

3-D Athena Widget set that looks like Motif

Formats an ASCII file for printing on a postscript printer

https://www.gnu.org/software/a2ps/

ASCII art library

http://aa-project.sourceforge.net/aalib/

Addressbook program with mutt mail client support

http://abook.sourceforge.net/

Wrapper script for Adobe Reader

Program for sending email messages for CVS repository commits

http://search.cpan.org/dist/activitymail/

ADAMEm is a portable Coleco ADAM and ColecoVision emulator

http://www.komkon.org/~dekogel/adamem.html

Adobe CMap collection

https://partners.adobe.com/asn/tech/type/ftechnotes.jsp

Database library for PHP

http://adodb.sourceforge.net

FTP-like shell for accessing Apple II disk images

Approximate grep (fast approximate pattern-matching tool)

File and directory integrity checker

https://aide.github.io/

Morse code training program

http://www.nongnu.org/aldo/

Interpreter for purely symbolic LISP

http://www.t3x.org/alisp/

Cross-platform library for games and multimedia programming

https://liballeg.org/

Mail and news client descended from Pine

https://alpineapp.email/

ALSA compatibility library

https://www.alsa-project.org/

ALSA compatibility library plugins

http://www.alsa-project.org/

AMSFonts PostScript Fonts (Adobe Type 1 format)

Extremely fast program for analysing WWW logfiles

http://www.analog.cx/

Version 2.2.x of Apache web server with prefork MPM.

http://httpd.apache.org/

Version 2.4.x of Apache web server

https://httpd.apache.org/

Apache RealTime log stats

http://www.webta.org/projects/apachetop/

Program to list application's resources

Apache Portability Library

https://apr.apache.org/

Create & extract files from DOS .ARC files

https://github.com/ani6al/arc

Asynchronous DNS resolver library

ftp://athena-dist.mit.edu/pub/ATHENA/ares/

Yet another download tool

https://aria2.github.io/

Open source implementation of the ARJ archiver

http://arj.sourceforge.net/

Text document format for writing short documents and man pages

https://github.com/asciidoc-py/asciidoc-py

Afterstep clock with some language extensions

Spelling checker with better suggestion logic than ispell

http://aspell.net/

Aspell German dictionary

http://lisa.goe.net/~bjacke/igerman98/

Ispell compatibility script for aspell

http://aspell.net/

Assisted Technology Provider module for GTK+

https://gitlab.gnome.org/GNOME/at-spi2-atk

Assistive Technology Service Provider Interface

https://gitlab.gnome.org/GNOME/at-spi2-core

GNOME accessibility toolkit (ATK)

https://developer.gnome.org/atk/

C++ wrapper for ATK API library

https://www.gtkmm.org/

Software for collecting and analyzing calls from different PBX models

http://www.atslog.com/en/about/

Generate configure scripts and related files

https://www.gnu.org/software/autoconf/

Wrapper script for GNU autoconf