Similar to LibreCAD
 - GephiGephi
 - GlassFishGlassFish
 - Google WaveGoogle Wave
 - GRASS GISGRASS GIS
 - GreasemonkeyGreasemonkey
 - GunicornGunicorn
 - Hack (プログラミング言語)Hack (programming language)
 - Hexagon (ソフトウェア)Hexagon (software)
- Hi-Def Life
 - HSQLDBHSQLDB
 - HTML TidyHTML Tidy
 - HTTrackHTTrack
 - HypertableHypertable
 - IIIMFInternet/Intranet Input Method Framework
 - IJCAD
 - IKVM.NETIKVM
 - InitngInitng
 - InnoDBInnoDB
 - IntelliCADIntelliCAD
 - IspellIspell
 - JACK Audio Connection KitJACK Audio Connection Kit
 - JigdoJigdo
 - K-Multimedia PlayerKMPlayer
 - K2Editor
 - KawaKawa (Scheme implementation)
 - KbdApple
 - KiwixKiwix
 - KonaWiki