MahApps's repositories
MahApps.Metro
A framework that allows developers to cobble together a better UI for their own WPF applications with minimal effort.
MahApps.Metro.IconPacks
Awesome icon packs for WPF and UWP in one library
IconPacks.Browser
The Browser for all available Icon packages from MahApps.Metro.IconPacks
Microsoft.DwayneNeed
Samples and reusable code for accomplishing interesting scenarios in WPF (incl. Dwayne Need's WPF AirspaceDecorator). https://microsoftdwayneneed.codeplex.com
mahapps.github.com
Old Website for Mahapps.Metro
mahapps.com
New web site for MahApps.Metro
MahApps.Metro.Resources
Old icon resources repository which will be no longer updated.
Avalonia.IconPacks
Awesome icon packs for AvaloniaUI in one library
AvalonControlLibrary
AvalonControlLibrary from CodePlex
SilverlightToolkit
The Silverlight Toolkit provides open source controls and components for Silverlight developers
WpfExtendedToolkit
A OpenSource Updated fork of https://github.com/xceedsoftware/wpftoolkit