Lazarus is a free cross-platform visual integrated development environment (IDE) for rapid application development (RAD) using the Free Pascal compiler, which supports dialects of Object Pascal, to varying degrees.
License: Open Source
Lazarus is an open-source IDE that focuses on Pascal programming with excellent cross-platform capabilities, while Xamarin Studio is a Microsoft product that specializes in mobile app development using C# and .NET. Lazarus is ideal for developers looking for a free solution for cross-platform desktop apps, whereas Xamarin is suited for building high-performance mobile applications.