Havoc Pennington
The Red Hat developer behind Metacity, GConf and D-Bus, and one of the people who started freedesktop.org so GNOME and KDE could share anything at all.
Pennington joined GNOME in the late 1990s, wrote the book GTK+/Gnome Application Development in 1999 and was hired by Red Hat. There he wrote the GConf configuration system and, in 2001, the Metacity window manager — deliberately "boring" and almost free of options, a stance he also argued in his essay on how every preference has a cost.
In 2000 he started freedesktop.org, a neutral home for specifications both desktops could follow: EWMH, .desktop files, startup notification. D-Bus, which he wrote from 2002 with KDE's DCOP as the model, became the clearest result. KDE 4 switched to it, and today nearly the whole Linux desktop talks over a bus he designed. He later left Red Hat for start-ups such as Litl and Typesafe.