Xamarin Studio is not available for Linux but there are plenty of alternatives that runs on Linux with similar functionality. The best Linux alternative is Eclipse, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to Xamarin Studio and many of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to Xamarin Studio are PyCharm (Freemium, Open Source), Apache NetBeans (Free, Open Source), Code::Blocks (Free, Open Source) and Qt Creator (Free, Open Source).
Python and Django IDE with refactorings, code completion, on-the-fly code analysis and other features, including version control integration, deployment, integration with issue trackers, and remote debugging.
Code::Blocks is a free C++ IDE built to meet the most demanding needs of its users. It is designed to be very extensible and fully configurable. An IDE with all the features a developer need, having a consistent look, feel and operation across platforms.
Lazarus is a cross-platform IDE for the Free Pascal compiler. It tries to offer a Delphi-like programming experience through its own 'Lazarus Component Library' and supporting many platforms like Windows, OSX, Linux, BSD, Android, iOS and more.
Aptana Studio is a complete web development environment that combines powerful authoring tools with a collection of online hosting and collaboration services that help you and your team do more. Includes support for PHP, CSS, FTP, and more...