Spyder (Scientific Python Development Environment) is a popular integrated development environment (IDE) for Python, designed by scientists, for scientists. It comes with a lot of handy features that are helpful in scientific computing, data analysis, and machine learning.

Key features of Spyder include:

1. Advanced Editor: It has an editor with features like syntax highlighting, introspection, and code completion.

2. Interactive Console: It includes an interactive Python console where you can run scripts line by line, check variables, etc. It also supports IPython.

3. Variable Explorer: This allows you to inspect and interact with your variables, which can be very helpful for data analysis.

4. Multi-language support: Although it’s designed for Python, Spyder also offers limited support for languages like Cython, IPython, etc.

5. Integration with popular libraries: Spyder has good integration with popular Python libraries such as NumPy, SciPy, Matplotlib, and others.

6. Debugging: It includes debugging capabilities, such as breakpoints, and the ability to step through code.

7. Documentation viewer: This allows you to view the documentation from within the IDE, which can be very convenient.

8. Profiling and code execution analysis: These tools help identify performance issues and optimize your code.

Spyder is open-source and free to use. It is often used in combination with the Anaconda Python distribution, which packages together many popular libraries for scientific Python computing.