Asteroids clone by Allen Smith

https://allenmonroesmith.bitbucket.io/Allenroids/

Mail and news client descended from Pine

https://alpineapp.email/

ALSA compatibility library

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

ALSA compatibility library plugins

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

ALSA compatibility utils

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

Amazon Simple Systems Manager Agent

https://github.com/aws/amazon-ssm-agent

Fast program for analysing WWW logfiles

http://www.analog.cx/

Andika TrueType fonts

https://software.sil.org/andika/

Integrated Development Environment for C and C++

http://anjuta.org/

Retrofuturism inspired monospaced programming font

https://github.com/benbusby/anomaly-mono

Fixed width sans designed especially for coders

https://www.ms-studio.com/FontSales/anonymouspro.html

Application for displaying Microsoft(R) Word documents

https://web.archive.org/web/20221207132720/http://www.winfield.demon.nl

ANother Tool for Language Recognition

https://www.antlr2.org/

Ncurses based arcade game with only 64 lines of code

http://aop.raffi.at/

Java- and XML-based build tool, conceptually similar to make

https://ant.apache.org/

Apache Commons Byte Code Engineering Library

https://commons.apache.org/proper/commons-bcel/

Java library for command line arguments and options

https://commons.apache.org/proper/commons-cli/

Implementations of common encoders and decoders

https://commons.apache.org/codec/

Classes that extend/augment the Java Collections Framework

https://commons.apache.org/proper/commons-collections/

Wrapper code to start/stop a Java application as a daemon

https://commons.apache.org/proper/commons-daemon/

Apache Commons Database Connection Pool

https://commons.apache.org/dbcp/

Package implementing the client side of the HTTP standard

https://hc.apache.org/httpclient-3.x/

Apache library with helper utilities for the java.lang API

https://commons.apache.org/proper/commons-lang/

Apache library with helper utilities for the java.lang API

https://commons.apache.org/proper/commons-lang/

Generic logging wrapper library

https://commons.apache.org/proper/commons-logging/

Apache Commons Object-pooling API

https://commons.apache.org/proper/commons-pool/

Library supporting Java primitive types

http://commons.apache.org/dormant/commons-primitives/

Version 2.4.x of Apache web server

https://httpd.apache.org/

Apache realtime log stats

https://github.com/tessus/apachetop

Automated Password Generator written in Go

https://github.com/wneessen/apg-go

APL385 Unicode monospaced code font

http://apl385.com/fonts

Program to list application's resources

Library to help with AppStream metadata

https://github.com/hughsie/appstream-glib/

GNUstep application wrapper

https://appwrapper.sourceforge.net/

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/

ICC compatible color management system

https://www.argyllcms.com/

Yet another download tool

https://aria2.github.io/ https://github.com/aria2/aria2

Open source implementation of the ARJ archiver

https://arj.sourceforge.net/

Set of (improved) artwiz fonts

https://artwizaleczapka.sourceforge.net/

Set of (improved) artwiz fonts

https://artwizaleczapka.sourceforge.net/

Set of (improved) artwiz fonts

https://artwizaleczapka.sourceforge.net/

Set of free fonts for X11 desktops

Text document format for writing short documents and man pages

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

Afterstep clock with some language extensions

Cross-platform C++ library for network and low-level I/O programming

https://think-async.com/Asio/

Spelling checker with better suggestion logic than ispell

http://aspell.net/

Ispell compatibility script for aspell

http://aspell.net/

Library to import various 3D model formats in a uniform manner

https://www.assimp.org/