| Alien-Gnuplot | module to find and validate the gnuplot executable | https://metacpan.org/release/Alien-Gnuplot | Other | |
| Alien-SDL | helper to get, build and use SDL libraries | https://metacpan.org/release/Alien-SDL | Other | |
| Alien-wxWidgets | Perl module for locating wxWidgets binaries | https://metacpan.org/release/Alien-wxWidgets | Other
GPLv2orlater | |
| Alienblaster | Classic 2D shoot 'em up | http://www.schwardtnet.de/alienblaster/ | GPLv2orlater
BSD 3Clause | |
| Aliens | Alien-shooting game for X-Window | http://www.newbreedsoftware.com/ | GPLv2 | |
| Align | Text filter tool that aligns columns | http://www.cs.indiana.edu/~kinzler/align/ | GPLv2orlater | |
| Aliki | Measurement tool for Impulse Responses | http://kokkinizita.linuxaudio.org/linuxaudio/downloads/index.html | GPLv2orlater | |
| Alist | Collects and stores information about systems | http://www.brains2bytes.com/alist/ | GPLv2 | |
| Alive | Keep-alive program for internet connections. | https://www.gnu.org/software/alive/ | GPLv3orlater | [[File:Heckert_gnu.small.png|30px]] |
| Alived | Simple daemon and client for sending keepalive messages. | https://www.gnu.org/software/alived/ | Other
GPLv2orlater | |
| AllCommerce | E-commerce/content application | http://allcommerce.sourceforge.net/ | GPLv2 | |
| AllKnowingDNS | tiny DNS server for IPv6 Reverse DNS | https://metacpan.org/release/AllKnowingDNS | Other | |
| AllPairs | Pairwise test combinations generator | http://sourceforge.net/apps/trac/allpairs/ | Expat | |
| AllTray | Software for docking any program. | https://launchpad.net/alltray | GPLv2 | |
| Allegro | Game programming library | http://alleg.sourceforge.net/ | SimplePermissive | |
| Allegro 4 | documentation for the Allegro library | http://www.liballeg.org | Zlib
Other
Expat
LGPLv2orlater | |
| Allegro 5 | documentation for the Allegro 5 library | http://liballeg.org/ | Zlib
Other
BSD 3Clause | |
| Alleyoop | Alleyoop is a GNOME front-end to the Valgrind memory checker. | http://alleyoop.sourceforge.net/ | GPLv3orlater | |
| Alliance | CAD tools | https://www-soc.lip6.fr/equipe-cian/logiciels/alliance/ | GPLv2orlater | |
| AllocPSA | automated online professional services | http://www.allocpsa.org/ | AGPLv3orlater | |
| Almanah | Application to ease management of a personal diary | http://live.gnome.org/Almanah Diary | GPLv3 | |
| Almclk | Sets an alarm on your terminal | http://www.bell-labs.com/wwexptools/almclk/ | GPLv2orlater | |
| Alnuth | GAP Alnuth - Algebraic number theory and an interface to PARI/GP | http://www.gap-system.org/Packages/alnuth.html | GPLv2orlater | |
| Alog | Logging framework for Ada (base). | https://www.codelabs.ch/alog/ | Other | |
| Alogg | Facilitates the use of Ogg/Vorbis streams with allegro | http://lyrian.obnix.com/alogg/ | LGPL | |
| Alot | Text mode MUA using notmuch mail | https://github.com/pazz/alot/ | Other
GPLv3orlater | |
| AlphaMail | A middleware-accelerated Web mail client. | http://sourceforge.net/projects/alphamail | GPLv2orlater | |
| Alpine | A screen-oriented message-handling tool- Alternatively Licensed Program for Internet News and Email | https://alpineapp.email/ | Apache2.0 | |
| Alpine3D | Distributed alpine surface processes model | https://models.slf.ch/p/alpine3d/ | LGPLv3orlater | |
| Alpy | Python bindings to the Allegro game programming library | http://pyallegro.sourceforge.net/ | X11 | |
| AlsaModularSynth | Realtime modular synthesizer for ALSA | http://alsamodular.sourceforge.net/ | ISC
GPLv2 | |
| Alsaequal | equalizer plugin for ALSA | http://www.thedigitalmachine.net/alsaequal.html | Other | |
| Alsaplayer | PCM (audio) player for ALSA | http://alsa-project.org/ | GPLv3orlater | |
| Alt | namespace for alternate module implementations | https://metacpan.org/release/Alt | Other | |
| Alt key | tool to help developers improve keyboard accelerators | http://www.qtrac.eu/alt key.html | Other | |
| Alt-Base | base class for alternate modules | https://metacpan.org/release/Alt-Base | Other | |
| Alt-ergo | Automatic theorem prover dedicated to program verification | http://alt-ergo.lri.fr | Other
LGPLv2 | |
| Altcdfenvs | BioConductor alternative CDF environments | http://bioconductor.org/packages/release/bioc/html/altcdfenvs.html | Other | |
| AlterMIME | Integrated email/mailpack manipulation utility | http://www.pldaniels.com/altermime/ | BSD AdClause | |
| Alterparagraphs | alternative implementations for ReportLab paragraph flowables. | http://www.dinu-gherman.net/tmp/alterparagraphs-README.html | GPLv3 | |
| Althea | IMAP E-Mail client for Gtk | http://althea.sourceforge.net/ | GPLv2orlater | |
| Altium2kicad | Altium to KiCad converter for PCB and schematics | https://github.com/thesourcerer8/altium2kicad | GPLv2 | |
| Altree | program to perform phylogeny-based association and localization analysis | http://claire.bardel.free.fr/software.html | Other
GPLv2orlater | |
| Alumni-OnLine | A PHP/DBMS-based program to make a connection between alumnis. | http://sourceforge.net/projects/alumni-online | GPL | |
| Am-utils | Berkeley automounter suite of utilities | http://www.am-utils.org/ | BSD AdClause | |
| AmSynth | two oscillator software synthesizer | http://code.google.com/p/amsynth/ | GPLv2orlater | |
| Amanda | Backs up multiple hosts to a single drive | http://www.amanda.org/ | | |
| Amap-align | Protein multiple alignment by sequence annealing | https://code.google.com/archive/p/amap-align/ | PublicDomain
GPLv2orlater | |
| Amara | library for XML processing in Python. | http://wiki.xml3k.org/Amara2 | Expat
Apache2.0 | |
| Amarok | Multimedia player suited for KDE | http://amarok.kde.org/ | GFDL
BSD 3Clause
GPLv2
LGPLv2.1 | |
