Klaviyo - Klaviyo helps brands own the customer experience, grow higher-value relationships, and deliver more personalized marketing experiences across email, mobile, and web.
wxWidgets - wxWidgets: Cross-Platform GUI Library
Criteo - Build, scale, and activate first-party audiences with The Commerce Media Platform.
Electron - Build cross platform desktop apps with web technologies
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.