Topcoat is described as 'brand new open source CSS library designed to help developers build web apps with an emphasis on speed. It evolved from the Adobe design language developed for Brackets, Edge Reflow, and feedback from the PhoneGap app developer community' and is an app in the Development category. There are more than 25 alternatives to Topcoat for a variety of platforms, including Online / Web-based, Self-Hosted solutions, Mac, Windows and Linux. The best alternative is Materialize, which is both free and Open Source. Other great apps like Topcoat are Foundation (Free, Open Source), Purecss (Free, Open Source), Tailwind CSS (Free, Open Source) and Element UI (Free, Open Source).