GNOME has an interesting progress history.<p>- Initially, Miguel De Icaza started GNOME in 1997, he also created the Gnumeric spreadsheet for GNOME, and when .NET was released, he together with Nat Friedman (CEO and Co-Founder of Github), started Helix Code which later become Ximian/Xamarin and Mono. Miguel De Icaza abandoned GNOME even before 2013, and finally left Linux in 2013.<p>- Several default apps in GNOME were written in C# Mono, namely F-Spot and Tomboy Notes.<p>- Nat Friedman also created the Beagle Desktop, which is a search-and-indexing tool for GNOME back in 2006.<p>- Ximian Desktop developed the Evolution Groupware Suite, to allow GNOME to be used in office environments. Evolution had become GNOME's standard email client.<p>- Eric Sink, which led the SpyGlass browser team that licensed the Mosaic browser, which had become the codebase for Internet Explorer, developed AbiWord, which is GNOME's standard word-processor.<p>- In 1999, Andy Hertzfeld from Apple together with other Apple engineers, started Eazel, which created the Nautilus File Manager, which is had become the standard file manager for GNOME.<p>- Novell Desktop introduces the Compiz compositor in 1999, also SLED10 has a new GNOME Main Menu, which become a standard menu for SuSE.<p>- Novell also spearheaded the Tango Desktop project, which provides theming consistency for GNOME and it's apps. Later, Tango Desktop was adopted by other projects as well.<p>- RedHat developed the NetworkManager layer, also, Robert Love from Xamarin (Now Google) contributed heavily to the project. NetworkManager, makes it easier to configure and switch WIFI networks in Gnome.<p>Several underlying tech that build GNOME comes from:<p>- GTK+ toolkit, that is the basis GNOME comes from GIMP Image Editor.<p>- GNOME has several WM throughout the years, starting with Sawfish, then MetaCity and then Mutter.<p>- Ubuntu having invested heavily on Compiz, tries to keep Compiz and GNOME 3, AFAIR, they have initially opposed the GNOME 3 direction of using Mutter and several GNOME 3 design principles, hence they have developed the Unity Desktop. I am not sure what mainline contribution that comes out from Unity, as I didn't follow after Unity.<p>GNOME was actually a fun project, several changes had happened to GNOME, but IMHO, it's a masterpiece out of orchestrated chaos.