Understand - Combines a powerful Code Editor together with an impressive array of static analysis tools that will change the way you work with code.

PyCharm - Python & Django IDE with intelligent code completion, on-the-fly error checking, quick-fixes, and much more...

Sourcetrail - Sourcetrail is a cross-platform source explorer for C/C++ and Java.

Spyder - The Scientific Python Development Environment

Source Insight - Source Insight is a programming editor & code browser with built-in live analysis for C/C++, C#, Java, and more; helping you understand large projects.

Thonny - Python IDE for beginners