I tend to look for areas where there's a gap in current functionality. I seek to contribute cross-platform support to existing "foundational" libraries where lack of platform support increases adoption barriers to adoption.
Active Projects in alphabetical order
Authenticode Signing Service and Client
Author and Maintainer
NuGet | GitHub
The project aims to make it easier to integrate Authenticode signing into a CI process by providing a secured API for submitting artifacts to be signed by a code signing cert held on the server.
Bouncy Castle
Maintainer of .NET Standard version
NuGet | GitHub | Web
Bouncy Castle is a crypto library with a wide range of cryptographic and hash algorithm support. I made it work as .NET Standard.
Humanizer
Maintainer and Contributer
Humanizer meets all your .NET needs for manipulating and displaying strings, enums, dates, times, timespans, numbers and quantities
MSBuild SDK Extras
Author and Maintainer
The MSBuild SDK Extras contains a few extra extensions to the SDK-style projects that are currently not available in the main SDK.
Reactive Extensions for .NET
Contributor and Maintainer
Reactive and Interactive Extensions for .NET. Part of the .NET Foundation
ReactiveUI
Maintainer and Contributor
Use the Reactive Extensions for .NET to create elegant, testable User Interfaces that run on any mobile or desktop platform.
xUnit
Contributor
Responsible for Xamarin.iOS, Xamarin.Android, Windows Phone App 8.1 and Windows Store 8 support.
xUnit for Devices
Author and Maintainer
Created xUnit runner apps for UWP, Xamarin.iOS and Xamarin.Android
xUnit Visual Studio Runners
Contributor
Responsible for UWP support.
Zeroconf
Author and Maintainer
Bonjour/mDNS support for .NET, UWP, Xamarin.iOS, Xamarin.Android and .NET Standard
Less active projects
DynamoDB Geospatial
Author and Maintainer of C#/.NET version
The Geo Library for Amazon DynamoDB enables .NET developers to easily create and query geospatial data. The library takes care of managing the geohash indexes required for fast and efficient execution of location-based queries over a table of items representing points of interest - latitude/longitude pairs.
Fluent Assertions
Was maintainer of project's official Xamarin packages before incorporated
MetroLog
Author and Maintainer
MetroLog is a lightweight logging framework designed for Windows Store and Windows Phone 8 apps. Although the API is based on NLog and log4net, the intention is that it's a very basic logging system.
MiFARE
Author and Maintainer
MiFARE is a PC/SC library for interacting with MiFARE Classic proximity cards supporting Windows Phone 8.1, Windows 8.1 (Store and Desktop) and UWP.
MVVM Light (Portable)
Author and Maintainer of Portable fork until May 2014. PCL version became base of main version.
Ninject
Author of Portable fork, Project Maintainer
Lightweight and lightning-fast .NET dependency injection framework.
NuSpec Reference Generator
Author and Maintainer
Generates the required NuSpec dependencies for dotnet, uap10.0 and netstandard. Full details in this post.
S2 Geometry Library for C#
Author and Maintainer of C#/.NET version
Port of Google's S2 Geometry Library. The library is be used to create GeoHashes for fast querying. The Java version is used by AWS for GeoSpatial queries in DynamoDB. S2 uses Hilbert Curves extensively.
WinRT HTTP Client Handler
Author and Maintainer
An HttpMessageHandler that lets you use the Windows Runtime IHttpFilter types
WinRT Time Zones
Author and Maintainer
Simple Time Zone conversion for WinRT, Windows Store, .NET and Windows Phone 8 apps.