Spyder

Spyder is an IDE for Python.

https://github.com/spyder-ide/spyder

It is complete, meaning it includes a source level debugger.

It is cross-platform.

It has code completion.

Installing it does not require admin rights on Windows, so I can use it everywhere.

It's unusual in that it opens an IPython interpreter as its console window so you can just type in random python there.

ArcGIS

My primary interest is to debug code running on Windows using arcpy. That means I have to use a 2.7 kernel. Does that mean installing arcpy in a different place or getting spyder to use the Python that ESRI installs?

Remote debugging

This is something I can do in Komodo, but I have not needed it in some time, so I have not tried it in Spyder yet. Some notes: https://groups.google.com/forum/#!searchin/spyderlib/remote%7Csort:relevance/spyderlib/usljVmI50GI/BdjmwX1k4nAJ

I wonder if I could use a copy on my Mac to debug code running on a Parallels machine.