First Floor Software, based in The Hague, The Netherlands, was formed in 2008 with the purpose of providing consultancy and building high-quality products related to XAML. Inspired by the release of Silverlight back in 2007 as an enabler to creating richer applications within the browser, First Floor Software has a primary focus on XAML technology related development.

First Floor Software is a privately owned company with no external funding.

Products and services

First Floor Software is an Independent Software Vendor (ISV) specialized in tools and components for XAML. XAML is the markup language by Microsoft used extensively in desktop, tablet and phone apps. The flagship product is XAML Spy, the visual runtime inspector for Silverlight, Windows Phone, Windows Store and WPF applications. XAML Spy is the successor of Silverlight Spy, the inspector tool for Silverlight and Phone 7 apps.

Next to product development, First Floor Software provides consultancy services to customers who require XAML expertise. Contact us if you want to learn more about how First Floor Software can help you build great XAML apps.

Koen Zwikstra

First Floor Software was founded by Koen Zwikstra, who previously has been involved in the development of many complex .NET based applications. Koen has proved to have a deep understanding of the .NET framework and the web client/server environment.



First Floor Software BV
Scheldestraat 116
2515 TG The Hague
The Netherlands
Trade register
Chamber of Commerce The Hague #59654171


Koen, the owner of First Floor Software, is on twitter! Join the conversation and follow @kozw.