| Air-quality-sensor | user space driver for AppliedSensor's Indoor Air Monitor | https://github.com/bwildenhain/air-quality-sensor | GPLv3orlater | |
| AirTraffic | Air Traffic Control simulation | http://airtraffic.sourceforge.net/ | GPLv2orlater | |
| Aircrack | Tools for auditing wireless networks ' | http://www.aircrack-ng.org/ | GPLv2orlater | |
| Aircrack-ng | wireless WEP/WPA cracking utilities | http://www.aircrack-ng.org/ | PublicDomain
GPLv2orlater with exception
GPLv2orlater
BSD 3Clause
BSD 2Clause
GPLv2 | |
| Airhook | a data delivery protocol, like TCP. | http://advogato.org/proj/Airhook/ | GPLv2orlater | |
| Airs | check for new TV episodes | https://github.com/jorgb/airs | GPLv2 | |
| Airspy-host | Tiny and efficient software defined radio receiver | http://airspy.com | Other
GPLv2orlater | |
| Airstrike | 2d dogfight game in the tradition of 'Biplanes' and 'BIP' | http://icculus.org/airstrike/ | GPLv2 | |
| Airtime | Free software radio automation software | http://www.sourcefabric.org/en/airtime/ | GPLv3 | |
| Aisleriot | GNOME solitaire card game collection | https://wiki.gnome.org/Apps/Aisleriot | Other
GPLv3orlater
LGPLv3 | |
| Aj-snapshot | make snapshots of JACK connections | http://aj-snapshot.sourceforge.net/ | GPLv3orlater | |
| AjaxMyTop | A Web-based tool featuring an AJAX user interface for monitoring a MySQL server. | http://sourceforge.net/projects/ajaxmytop/ | GPLv2orlater | |
| Ajaxterm | Web based terminal written in Python | http://antony.lesuisse.org/qweb/trac/wiki/AjaxTerm | PublicDomain
Other
GPLv2 | |
| Ajenti | Ajenti is a GNU/Linux & BSD modular server admin panel | https://ajenti.org/ | Expat | |
| Akfquiz | Write quiz-games and psychotests. | https://www.nongnu.org/akfquiz/ | GPLv3orlater | |
| Akregator | RSS/Atom feed reader and aggregator for KDE | https://userbase.kde.org/Akregator | GPLv2 | |
| Alacritty | A Wayland-native GPU-accelerated terminal emulator written in Rust | https://github.com/alacritty/alacritty | | |
| Alarm Pinger | Monitors IP devices by ICMP echo requests | https://github.com/Jajcus/apinger | GPLv2 | |
| Alarm-clock-applet | Alarm Clock applet | http://alarm-clock.pseudoberries.com/ | GPLv2orlater | |
| Albino | Ruby wrapper for pygmentize | http://github.com/github/albino | Expat | |
| Album Cover Art Downloader 2 | Downloads images from a collection of albums | http://www.unrealvoodoo.org/projects/albumart | GPLv2orlater | |
| AlbumEasy | Software for creating custom stamp album pages | https://www.thestampweb.com/albumeasy | GPLv3orlater | |
| Alchemist | A functional, Ruby DSL for casting, transforming and transposing objects | https://github.com/acumenbrands/alchemist | X11 | |
| Ald | The Assembly Language Debugger is a tool for debugging executable programs at the assembly level. | http://ald.sourceforge.net | GPLv2orlater | |
| Aldo | Morse code tutor | http://www.nongnu.org/aldo/ | GPLv2orlater | |
| Alembic | lightweight database migration tool for SQLAlchemy | http://www.bitbucket.org/zzzeek/alembic | Other | |
| Alerttail | A tool to execute actions when specific text has been written to a file. | https://sourceforge.net/projects/alerttail/?source=navbar | GPLv2orlater | |
| Aletheia | Aletheia is a decentralised open access publishing platform for scientific research. | https://aletheia-foundation.io/ | GPL | |
| Alex4 | Alex the Allegator 4 - a retro platform game | http://allegator.sourceforge.net/ | GPLv2orlater | |
| Alexandria | Access to electronic content and services for the blind. | https://www.gnu.org/software/alexandria/ | GPLv2orlater | |
| Alexis FTP (aftp) | an FTP library and a background FTP tool. | http://aftp.sourceforge.net/ | GPLv2orlater | |
| Alexis Makes (amake) | a make tool which uses powerful pattern transformation enabling a single makefile to automatically handle the compilation of any level of directory hierachy. | http://amake.sourceforge.net/ | GPLv2orlater | |
| Alf.io | Ticket reservation system | https://alf.io | GPLv3 | |
| Alfandega Firewall | Implements iptables-based firewalls | http://alfandega.sourceforge.net/ | GPLv2 | |
| Alfresco | Business document management | http://www.alfresco.com/products/community | LGPLv3 | |
| Algart | Java libraries for processing arrays and matrices, including image processing | http://algart.net/java/AlgART/ | Expat | |
| Alglib | Development files for the alglib library | http://www.alglib.net/ | Other
GPLv2orlater | |
| AlgoBox | algorithmics introduction - French UI | http://www.xm1math.net/algobox/ | Other
GPLv2orlater | |
| Algol 68 Genie | A fairly fully featured Algol 68 interpreter | http://www.xs4all.nl/~jmvdveer/algol.html | GPLv2orlater
GPLv3 | |
| Algorithm-C3 | Perl module for merging hierarchies using the C3 algorithm | https://metacpan.org/release/Algorithm-C3 | Other | |
| Algorithm-Combinatorics | module for the efficient generation of combinatorial sequences | https://metacpan.org/release/Algorithm-Combinatorics | Other | |
| Algorithm-Diff | module to find differences between files | https://metacpan.org/release/Algorithm-Diff | Other | |
| Algorithm-Diff-XS | module to find differences between files (XS accelerated) | https://metacpan.org/release/Algorithm-Diff-XS | Other | |
| Algorithm-LBFGS | Perl interface to an L-BFGS non-linear optimization algorithm | https://metacpan.org/release/Algorithm-LBFGS | Other | |
| Algorithm-Munkres | extension for Munkres' solution to Assignment problem | https://metacpan.org/release/Algorithm-Munkres | Other
GPLv2orlater | |
| Algorithm-Permute | module to perform permutations with object oriented interface | https://metacpan.org/release/Algorithm-Permute | Other | |
| Alias | module for accessing perl variables through aliases | https://metacpan.org/release/Alias | Other | |
| Aliased | Perl module to provide aliases of class names | https://metacpan.org/release/aliased | Other | |
| Alien | Converts between different free software packaging formats | https://joeyh.name/code/alien/ | GPLv2 | |
| Alien hunter | Interpolated Variable Order Motifs to identify horizontally acquired DNA | http://www.sanger.ac.uk/resources/software/alien hunter.html | Other | |
