What's In There? (continued)

Many graphical toolkits - Qt, Gtk, InterViews, wxWindows...

Desktop Environments - Fresco, KDE, GNOME, CDE...

Databases - Oracle, Informix, Sybase, Postgres, MySql...

Middleware - CORBA, Web Servers, application servers, transaction monitors (BEA), COM(!)...

Linux-specific extensions - Kernel loadable modules, PAM ("stolen" from Solaris).